Extract images from PDF without resampling, in python?
Try below code. it will extract all image from pdf.
import sys
import PyPDF2
from PIL import Image
pdf=sys.argv[1]
print(pdf)
input1 = PyPDF2.PdfFileReader(open(pdf, "rb"))
for x in range(0,input1.numPages):
xObject=input1.getPage(x)
xObject = xObject['/Resources']['/XObject'].getObject()
for obj in xObject:
if xObject[obj]['/Subtype'] == '/Image':
size = (xObject[obj]['/Width'], xObject[obj]['/Height'])
print(size)
data = xObject[obj]._data
#print(data)
print(xObject[obj]['/Filter'])
if xObject[obj]['/Filter'][0] == '/DCTDecode':
img_name=str(x)+".jpg"
print(img_name)
img = open(img_name, "wb")
img.write(data)
img.close()
print(str(x)+" is done")
How to view/delete local storage in Firefox?
Try this, it works for me:
var storage = null;
setLocalStorage();
function setLocalStorage() {
storage = (localStorage ? localStorage : (window.content.localStorage ? window.content.localStorage : null));
try {
storage.setItem('test_key', 'test_value');//verify if posible saving in the current storage
}
catch (e) {
if (e.name == "NS_ERROR_FILE_CORRUPTED") {
storage = sessionStorage ? sessionStorage : null;//set the new storage if fails
}
}
}
How to run cron job every 2 hours
To Enter into crontab :
crontab -e
write this into the file:
0 */2 * * * python/php/java yourfilepath
Example :0 */2 * * * python ec2-user/home/demo.py
and make sure you have keep one blank line after the last cron job in your crontab file
Notepad++ - How can I replace blank lines
This should get your sorted:
- Highlight from the end of the first line, to the very beginning of the third line.
- Use the
Ctrl + H
to bring up the 'Find and Replace' window.
- The highlighed region will already be plased in the 'Find' textbox.
- Replace with:
\r\n
- 'Replace All' will then remove all the additional line spaces not required.
Here's how it should look:
How to encode text to base64 in python
Whilst you can of course use the base64
module, you can also to use the codecs
module (referred to in your error message) for binary encodings (meaning non-standard & non-text encodings).
For example:
import codecs
my_bytes = b"Hello World!"
codecs.encode(my_bytes, "base64")
codecs.encode(my_bytes, "hex")
codecs.encode(my_bytes, "zip")
codecs.encode(my_bytes, "bz2")
This can come in useful for large data as you can chain them to get compressed and json-serializable values:
my_large_bytes = my_bytes * 10000
codecs.decode(
codecs.encode(
codecs.encode(
my_large_bytes,
"zip"
),
"base64"),
"utf8"
)
Refs:
What is the correct way to write HTML using Javascript?
document.write()
doesn't work with XHTML. It's executed after the page has finished loading and does nothing more than write out a string of HTML.
Since the actual in-memory representation of HTML is the DOM, the best way to update a given page is to manipulate the DOM directly.
The way you'd go about doing this would be to programmatically create your nodes and then attach them to an existing place in the DOM. For [purposes of a contrived] example, assuming that I've got a div
element maintaining an ID
attribute of "header," then I could introduce some dynamic text by doing this:
// create my text
var sHeader = document.createTextNode('Hello world!');
// create an element for the text and append it
var spanHeader = document.createElement('span');
spanHeader.appendChild(sHeader);
// grab a reference to the div header
var divHeader = document.getElementById('header');
// append the new element to the header
divHeader.appendChild(spanHeader);
<meta charset="utf-8"> vs <meta http-equiv="Content-Type">
While not contesting the other answers, I think the following is worthy of mentioning.
- The “long” (
http-equiv
) notation and the “short” one are equal, whichever comes first wins;
- Web server headers will override all the
<meta>
tags;
- BOM (Byte order mark) will override everything, and in many cases it will affect html 4 (and probably other stuff, too);
- If you don't declare any encoding, you will probably get your text in “fallback text encoding” that is defined your browser. Neither in Firefox nor in Chrome it's utf-8;
- In absence of other clues the browser will attempt to read your document as if it was in ASCII to get the encoding, so you can't use any weird encodings (utf-16 with BOM should do, though);
- While the specs say that the encoding declaration must be within the first 512 bytes of the document, most browsers will try reading more than that.
You can test by running echo 'HTTP/1.1 200 OK\r\nContent-type: text/html; charset=windows-1251\r\n\r\n\xef\xbb\xbf<!DOCTYPE html><html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"><meta charset="windows-1251"><title>??????</title></head><body>??????</body></html>' | nc -lp 4500
and pointing your browser at localhost:4500
. (Of course you will want to change or remove parts. The BOM part is \xef\xbb\xbf
. Be wary of the encoding of your shell.)
Please mind that it's very important that you explicitly declare the encoding. Letting browsers guess can lead to security issues.
How to quickly form groups (quartiles, deciles, etc) by ordering column(s) in a data frame
The method I use is one of these or Hmisc::cut2(value, g=4)
:
temp$quartile <- with(temp, cut(value,
breaks=quantile(value, probs=seq(0,1, by=0.25), na.rm=TRUE),
include.lowest=TRUE))
An alternate might be:
temp$quartile <- with(temp, factor(
findInterval( val, c(-Inf,
quantile(val, probs=c(0.25, .5, .75)), Inf) , na.rm=TRUE),
labels=c("Q1","Q2","Q3","Q4")
))
The first one has the side-effect of labeling the quartiles with the values, which I consider a "good thing", but if it were not "good for you", or the valid problems raised in the comments were a concern you could go with version 2. You can use labels=
in cut
, or you could add this line to your code:
temp$quartile <- factor(temp$quartile, levels=c("1","2","3","4") )
Or even quicker but slightly more obscure in how it works, although it is no longer a factor, but rather a numeric vector:
temp$quartile <- as.numeric(temp$quartile)
WPF: ItemsControl with scrollbar (ScrollViewer)
To get a scrollbar for an ItemsControl
, you can host it in a ScrollViewer
like this:
<ScrollViewer VerticalScrollBarVisibility="Auto">
<ItemsControl>
<uc:UcSpeler />
<uc:UcSpeler />
<uc:UcSpeler />
<uc:UcSpeler />
<uc:UcSpeler />
</ItemsControl>
</ScrollViewer>
Best way to check for IE less than 9 in JavaScript without library
bah to conditional comments! Conditional code all the way!!! (silly IE)
<script type="text/javascript">
/*@cc_on
var IE_LT_9 = (@_jscript_version < 9);
@*/
</script>
Seriously though, just throwing this out there in case it suits you better... they're the same thing, this can just be in a .js file instead of inline HTML
Note: it is entirely coincidental that the jscript_version check is "9" here. Setting it to 8, 7, etc will NOT check "is IE8", you'd need to lookup the jscript versions for those browsers.
Is there a way to run Python on Android?
As a Python lover and Android programmer, I'm sad to say this is not a good way to go. There are two problems:
One problem is that there is a lot more than just a programming language to the Android development tools. A lot of the Android graphics involve XML files to configure the display, similar to HTML. The built-in java objects are integrated with this XML layout, and it's a lot easier than writing your code to go from logic to bitmap.
The other problem is that the G1 (and probably other Android devices for the near future) are not that fast. 200 MHz processors and RAM is very limited. Even in Java, you have to do a decent amount of rewriting-to-avoid-more-object-creation if you want to make your app perfectly smooth. Python is going to be too slow for a while still on mobile devices.
ANTLR: Is there a simple example?
For Antlr 4 the java code generation process is below:-
java -cp antlr-4.5.3-complete.jar org.antlr.v4.Tool Exp.g
Update your jar name in classpath accordingly.
How can I check file size in Python?
You need the st_size
property of the object returned by os.stat
. You can get it by either using pathlib
(Python 3.4+):
>>> from pathlib import Path
>>> Path('somefile.txt').stat()
os.stat_result(st_mode=33188, st_ino=6419862, st_dev=16777220, st_nlink=1, st_uid=501, st_gid=20, st_size=1564, st_atime=1584299303, st_mtime=1584299400, st_ctime=1584299400)
>>> Path('somefile.txt').stat().st_size
1564
or using os.stat
:
>>> import os
>>> os.stat('somefile.txt')
os.stat_result(st_mode=33188, st_ino=6419862, st_dev=16777220, st_nlink=1, st_uid=501, st_gid=20, st_size=1564, st_atime=1584299303, st_mtime=1584299400, st_ctime=1584299400)
>>> os.stat('somefile.txt').st_size
1564
Output is in bytes.
SyntaxError: non-default argument follows default argument
You can't have a non-keyword argument after a keyword argument.
Make sure you re-arrange your function arguments like so:
def a(len1,til,hgt=len1,col=0):
system('mode con cols='+len1,'lines='+hgt)
system('title',til)
system('color',col)
a(64,"hi",25,"0b")
Find an element in a list of tuples
Or takewhile
, ( addition to this, example of more values is shown ):
>>> a= [(1,2),(1,4),(3,5),(5,7),(0,2)]
>>> import itertools
>>> list(itertools.takewhile(lambda x: x[0]==1,a))
[(1, 2), (1, 4)]
>>>
if unsorted, like:
>>> a= [(1,2),(3,5),(1,4),(5,7)]
>>> import itertools
>>> list(itertools.takewhile(lambda x: x[0]==1,sorted(a,key=lambda x: x[0]==1)))
[(1, 2), (1, 4)]
>>>
Include files from parent or other directory
In laymans terms, and practicality, I see this as an old DOS trick/thing. Whoa! What was that? DOS? Never heard of it!
".." backs you out of the current sub-directory one time to a higher folder/directory, and .. enter typed twice backs you out too 2 higher parent folders. Keep adding the ".. enter" back to back and you will soon find yourself at the top level of the directory.
As for Newbies to understand this better, consider this (in terms of the home PC or "C:\ drive" if you know what that means, rather than the web-servers/host "root directory" ). While your at it, Consider your website existing somewhere on your home PC's hard drive, buried in some folder under the C:\ drive. Lastly, you can think of it as ".." is back one directory and "/" is forward one directory/folder.
Now!
If you are using the command prompt and are within the "myDocuments" folder of your PC you must back out of that folder to get closer to the higher directory "C:\" by typing the "../".
If you wanted to access a file that is located in the widows directory while you are still in the myDocuments folder you would theoretically type ../windows; in reality of DOS command prompt you would simply type .., but I am setting you up for the web. The / redirects forward to another directory naturally.
Using "myDocuments" lets pretend that you created 2 folders within it called "PHP1" and "PHP2", in such we now have the folders:
- C:\myDocuments\PHP1
- C:\myDocuments\PHP2
In PHP1 you place a file called index.php. and in PHP2 folder you placed a file called Found.php. it now becomes:
- C:\myDocuments\PHP1\index.php
- C:\myDocuments\PHP2\found.php
Inside the
C:\myDocuments\PHP1\index.php file you would need to edit and type something like:
<?php include ('../php2/found.php')?>
The ../ is positional thus it considers your current file location "C:\myDocuments\PHP1\index.php" and is a directive telling it to back out of PHP1 directory and enter or move forward into PHP2 directory to look for the Found.php file. But does it read it? See my thoughts on trouble shooting below.
Now! suppose you have 1 folder PHP1 and a sub-folder PHP2:
you would simply reference/code
<?php include('/PHP2/found.php') ?>
as PHP2 exist as a sub-directory, below or within PHP1 directory.
If the above does not work it may have something to do with access/htaccess or permission to the directory or a typo. To enhance this...getting into trouble shooting...If the "found.php" file has errors/typo's within it, it will crash upon rendering at the error, such could be the reason (require/require_once) that you are experiencing the illusion that it is not changing directories or accessing the file.
At last thought on the matter, you may need to instantiate your functions or references in order to use the included/require "whatever" by creating a new variable or object such as
$newObject = new nameobject("origianlThingy");
Remember, just because you are including/requiring something, sometimes means just that, it is included/required to run, but it might need to be recreated to make it active or access it. New will surely re-create an instance of it "if it is readable" and make it available within the current document while preserving the original. However you should reference the newly created variable $newObject in all instances....if its global.
To put this in perspective of some web host account; the web host is some whopping over sized hard-drive (like that on your PC) and your domain is nothing more than a folder they have assigned to you. Your folder is called the root. Inside that folder you can do anything you are allowed to do.
your "one of many ways" to move between directories/folders is to use the ../
however many times to back out of your current in reference to folder position you want to find.
In my drunken state I realize that I know too much to be sane, and not
enough to be insane!"
Python 3 print without parenthesis
Although you need a pair of parentheses to print in Python 3, you no longer need a space after print
, because it's a function. So that's only a single extra character.
If you still find typing a single pair of parentheses to be "unnecessarily time-consuming," you can do p = print
and save a few characters that way. Because you can bind new references to functions but not to keywords, you can only do this print
shortcut in Python 3.
Python 2:
>>> p = print
File "<stdin>", line 1
p = print
^
SyntaxError: invalid syntax
Python 3:
>>> p = print
>>> p('hello')
hello
It'll make your code less readable, but you'll save those few characters every time you print something.
Tools for making latex tables in R
The stargazer package is another good option. It supports objects from many commonly used functions and packages (lm, glm, svyreg, survival, pscl, AER), as well as from zelig. In addition to regression tables, it can also output summary statistics for data frames, or directly output the content of data frames.
How to catch integer(0)?
That is R's way of printing a zero length vector (an integer one), so you could test for a
being of length 0:
R> length(a)
[1] 0
It might be worth rethinking the strategy you are using to identify which elements you want, but without further specific details it is difficult to suggest an alternative strategy.
Hibernate-sequence doesn't exist
If you are using Hibernate version prior to Hibernate5 @GeneratedValue(strategy = GenerationType.IDENTITY)
works like a charm. But post Hibernate5 the following fix is necessary.
@Id
@GeneratedValue(strategy= GenerationType.AUTO,generator="native")
@GenericGenerator(name = "native",strategy = "native")
private Long id;
DDL
`id` BIGINT(20) NOT NULL AUTO_INCREMENT PRIMARY KEY
REASON
Excerpt from hibernate-issue
Currently, if the hibernate.id.new_generator_mappings is set to false,
@GeneratedValue(strategy = GenerationType.AUTO) is mapped to native.
If this property is true (which is the defult value in 5.x), the
@GeneratedValue(strategy = GenerationType.AUTO) is always mapped to
SequenceStyleGenerator.
For this reason, on any database that does not support sequences
natively (e.g. MySQL) we are going to use the TABLE generator instead
of IDENTITY.
However, TABLE generator, although more portable, uses a separate
transaction every time a value is being fetched from the database. In
fact, even if the IDENTITY disables JDBC batch updates and the TABLE
generator uses the pooled optimizer, the IDENTITY still scales better.
Add column in dataframe from list
Just assign the list directly:
df['new_col'] = mylist
Alternative
Convert the list to a series or array and then assign:
se = pd.Series(mylist)
df['new_col'] = se.values
or
df['new_col'] = np.array(mylist)
Return the characters after Nth character in a string
If your numbers are always 4 digits long:
=RIGHT(A1,LEN(A1)-5) //'0001 Baseball' returns Baseball
If the numbers are variable (i.e. could be more or less than 4 digits) then:
=RIGHT(A1,LEN(A1)-FIND(" ",A1,1)) //'123456 Baseball’ returns Baseball
Check if value is in select list with JQuery
Use the Attribute Equals Selector
var thevalue = 'foo';
var exists = 0 != $('#select-box option[value='+thevalue+']').length;
If the option's value was set via Javascript, that will not work. In this case we can do the following:
var exists = false;
$('#select-box option').each(function(){
if (this.value == 'bar') {
exists = true;
return false;
}
});
Get statistics for each group (such as count, mean, etc) using pandas GroupBy?
Returns count
, mean
, std
, and other useful statistics per-group.
df.groupby(['A', 'B'])['C'].describe()
count mean std min 25% 50% 75% max
A B
bar one 1.0 0.40 NaN 0.40 0.40 0.40 0.40 0.40
three 1.0 2.24 NaN 2.24 2.24 2.24 2.24 2.24
two 1.0 -0.98 NaN -0.98 -0.98 -0.98 -0.98 -0.98
foo one 2.0 1.36 0.58 0.95 1.15 1.36 1.56 1.76
three 1.0 -0.15 NaN -0.15 -0.15 -0.15 -0.15 -0.15
two 2.0 1.42 0.63 0.98 1.20 1.42 1.65 1.87
To get specific statistics, just select them,
df.groupby(['A', 'B'])['C'].describe()[['count', 'mean']]
count mean
A B
bar one 1.0 0.400157
three 1.0 2.240893
two 1.0 -0.977278
foo one 2.0 1.357070
three 1.0 -0.151357
two 2.0 1.423148
describe
works for multiple columns (change ['C']
to ['C', 'D']
—or remove it altogether—and see what happens, the result is a MultiIndexed columned dataframe).
You also get different statistics for string data. Here's an example,
df2 = df.assign(D=list('aaabbccc')).sample(n=100, replace=True)
with pd.option_context('precision', 2):
display(df2.groupby(['A', 'B'])
.describe(include='all')
.dropna(how='all', axis=1))
C D
count mean std min 25% 50% 75% max count unique top freq
A B
bar one 14.0 0.40 5.76e-17 0.40 0.40 0.40 0.40 0.40 14 1 a 14
three 14.0 2.24 4.61e-16 2.24 2.24 2.24 2.24 2.24 14 1 b 14
two 9.0 -0.98 0.00e+00 -0.98 -0.98 -0.98 -0.98 -0.98 9 1 c 9
foo one 22.0 1.43 4.10e-01 0.95 0.95 1.76 1.76 1.76 22 2 a 13
three 15.0 -0.15 0.00e+00 -0.15 -0.15 -0.15 -0.15 -0.15 15 1 c 15
two 26.0 1.49 4.48e-01 0.98 0.98 1.87 1.87 1.87 26 2 b 15
For more information, see the documentation.
This is available from pandas 1.1 if you just want to capture the size of every group, this cuts out the GroupBy
and is faster.
df.value_counts(subset=['col1', 'col2'])
Minimal Example
# Setup
np.random.seed(0)
df = pd.DataFrame({'A' : ['foo', 'bar', 'foo', 'bar',
'foo', 'bar', 'foo', 'foo'],
'B' : ['one', 'one', 'two', 'three',
'two', 'two', 'one', 'three'],
'C' : np.random.randn(8),
'D' : np.random.randn(8)})
df.value_counts(['A', 'B'])
A B
foo two 2
one 2
three 1
bar two 1
three 1
one 1
dtype: int64
If you didn't find what you were looking for above, the User Guide has a comprehensive listing of supported statical analysis, correlation, and regression tools.
How can you get the build/version number of your Android application?
Use:
try {
PackageInfo pInfo = context.getPackageManager().getPackageInfo(context.getPackageName(), 0);
String version = pInfo.versionName;
} catch (PackageManager.NameNotFoundException e) {
e.printStackTrace();
}
And you can get the version code by using this
int verCode = pInfo.versionCode;
Avoid web.config inheritance in child web application using inheritInChildApplications
I put everything into:
<location path="." inheritInChildApplications="false">
....
</location>
except: <configSections/>
, <connectionStrings/>
and <runtime/>
.
There are some cases when we don't want to inherit some secions from <configSections />
, but we can't put <section/>
tag into <location/>
, so we have to create a <secionGroup />
and put our unwanted sections into that group. Section groups can be later inserted into a location tag.
So we have to change this:
<configSections>
<section name="unwantedSection" />
</configSections>
Into:
<configSections>
<sectionGroup name="myNotInheritedSections">
<section name="unwantedSection" />
</sectionGroup>
</configSections>
<location path="." inheritInChildApplications="false">
<myNotInheritedSections>
<unwantedSection />
</myNotInheritedSections>
</location>
Find MongoDB records where array field is not empty
{ $where: "this.pictures.length > 1" }
use the $where and pass the this.field_name.length which return the size of array field and check it by comparing with number. if any array have any value than array size must be at least 1. so all the array field have length more than one, it means it have some data in that array
What is the difference between putting a property on application.yml or bootstrap.yml in spring boot?
This answer has been very beautifully explained in book "Microservices Interview Questions, For Java Developers (Spring Boot, Spring Cloud, Cloud
Native Applications) by Munish Chandel, Version 1.30, 25.03.2018.
The following content has been taken from this book, and total credit
for this answer goes to the Author of the book i.e. Munish
Chandel
application.yml
application.yml/application.properties file is specific to Spring Boot applications. Unless you change the location of external properties of an application, spring boot will always load application.yml from the following location:
/src/main/resources/application.yml
You can store all the external properties for your application in this file. Common properties that are available in any Spring Boot project can be found at: https://docs.spring.io/spring-boot/docs/current/reference/html/common-application-properties.html You can customize these properties as per your application needs. Sample file is shown below:
spring:
application:
name: foobar
datasource:
driverClassName: com.mysql.jdbc.Driver
url: jdbc:mysql://localhost/test
server:
port: 9000
bootstrap.yml
bootstrap.yml on the other hand is specific to spring-cloud-config and is loaded before the application.yml
bootstrap.yml is only needed if you are using Spring Cloud and your microservice configuration is stored on a remote Spring Cloud Config Server.
Important points about bootstrap.yml
- When used with Spring Cloud Config server, you shall specify the application-name and config git location using below properties.
spring.application.name: "application-name"
spring.cloud.config.server.git.uri: "git-uri-config"
- When used with microservices (other than cloud config server), we need to specify the
application name and location of config server using below properties
spring.application.name:
spring.cloud.config.uri:
- This properties file can contain other configuration relevant to Spring Cloud environment for e.g. eureka server location, encryption/decryption related properties.
Upon startup, Spring Cloud makes an HTTP(S) call to the Spring Cloud Config Server with the name of the application and retrieves back that application’s configuration.
application.yml contains the default configuration for the microservice and any configuration retrieved (from cloud config server) during the bootstrap process will override configuration defined in application.yml
How to call a REST web service API from JavaScript?
Your Javascript:
function UserAction() {
var xhttp = new XMLHttpRequest();
xhttp.onreadystatechange = function() {
if (this.readyState == 4 && this.status == 200) {
alert(this.responseText);
}
};
xhttp.open("POST", "Your Rest URL Here", true);
xhttp.setRequestHeader("Content-type", "application/json");
xhttp.send("Your JSON Data Here");
}
Your Button action::
<button type="submit" onclick="UserAction()">Search</button>
For more info go through the following link (Updated 2017/01/11)
Check object empty
In Java, you can verify using Object utils.
import static java.util.Objects.isNull;
if(IsNull(yourObject)){
//your block here
}
execute function after complete page load
call a function after complete page load set time out
_x000D_
_x000D_
setTimeout(function() {_x000D_
var val = $('.GridStyle tr:nth-child(2) td:nth-child(4)').text();_x000D_
for(var i, j = 0; i = ddl2.options[j]; j++) {_x000D_
if(i.text == val) { _x000D_
ddl2.selectedIndex = i.index;_x000D_
break;_x000D_
}_x000D_
} _x000D_
}, 1000);
_x000D_
_x000D_
_x000D_
AttributeError: Can only use .dt accessor with datetimelike values
Your problem here is that to_datetime
silently failed so the dtype remained as str/object
, if you set param errors='coerce'
then if the conversion fails for any particular string then those rows are set to NaT
.
df['Date'] = pd.to_datetime(df['Date'], errors='coerce')
So you need to find out what is wrong with those specific row values.
See the docs
Java equivalent to #region in C#
In Eclipse you can collapse the brackets wrapping variable region block. The closest is to do something like this:
public class counter_class
{
{ // Region
int variable = 0;
}
}
How to insert a column in a specific position in oracle without dropping and recreating the table?
In 12c you can make use of the fact that columns which are set from invisible to visible are displayed as the last column of the table:
Tips and Tricks: Invisible Columns in Oracle Database 12c
Maybe that is the 'trick' @jeffrey-kemp was talking about in his comment, but the link there does not work anymore.
Example:
ALTER TABLE my_tab ADD (col_3 NUMBER(10));
ALTER TABLE my_tab MODIFY (
col_1 invisible,
col_2 invisible
);
ALTER TABLE my_tab MODIFY (
col_1 visible,
col_2 visible
);
Now col_3 would be displayed first in a SELECT * FROM my_tab
statement.
Note: This does not change the physical order of the columns on disk, but in most cases that is not what you want to do anyway. If you really want to change the physical order, you can use the DBMS_REDEFINITION package.
New Line Issue when copying data from SQL Server 2012 to Excel
My best guess is that this is not a bug, but a feature of Sql 2012. ;-)
In other contexts, you'd be happy to retain your cr-lf's, like when copying a big chunk of text. It's just that it doesn't work well in your situation.
You could always strip them out in your select. This would make your query for as you intend in both versions:
select REPLACE(col, CHAR(13) + CHAR(10), ', ') from table
How to automatically allow blocked content in IE?
You have two options:
Use a Mark of the Web. This will enable a single html page to load. It See here for details. To do this, add the following to your web page below the doctype and above the html tag:
<!-- saved from url=(0014)about:internet -->
Disable this feature. To do so go to Internet Options->Advanced->Security->Allow Active Content... Then close IE. When you restart IE, it will not give you this error.
Reverse of JSON.stringify?
http://jsbin.com/tidob/1/edit?js,console,output
The native JSON object includes two key methods.
1. JSON.parse()
2. JSON.stringify()
The JSON.parse()
method parses a JSON string - i.e. reconstructing the original JavaScript object
var jsObject = JSON.parse(jsonString);
JSON.stringify() method accepts a JavaScript object and returns its JSON equivalent.
var jsonString = JSON.stringify(jsObject);
GoTo Next Iteration in For Loop in java
As mentioned in all other answers, the keyword continue
will skip to the end of the current iteration.
Additionally you can label your loop starts and then use continue [labelname];
or break [labelname];
to control what's going on in nested loops:
loop1: for (int i = 1; i < 10; i++) {
loop2: for (int j = 1; j < 10; j++) {
if (i + j == 10)
continue loop1;
System.out.print(j);
}
System.out.println();
}
Programmatically scroll to a specific position in an Android ListView
I have set OnGroupExpandListener and override onGroupExpand() as:
and use setSelectionFromTop() method which
Sets the selected item and positions the selection y pixels from the top edge of the ListView. (If in touch mode, the item will not be selected but it will still be positioned appropriately.) (android docs)
yourlist.setOnGroupExpandListener (new ExpandableListView.OnGroupExpandListener()
{
@Override
public void onGroupExpand(int groupPosition) {
expList.setSelectionFromTop(groupPosition, 0);
//your other code
}
});
No module named MySQLdb
Note this is not tested for python 3.x
In CMD
pip install wheel
pip install pymysql
in settings.py
import pymysql
pymysql.install_as_MySQLdb()
It worked with me
How do I encode a JavaScript object as JSON?
All major browsers now include native JSON encoding/decoding.
// To encode an object (This produces a string)
var json_str = JSON.stringify(myobject);
// To decode (This produces an object)
var obj = JSON.parse(json_str);
Note that only valid JSON data will be encoded. For example:
var obj = {'foo': 1, 'bar': (function (x) { return x; })}
JSON.stringify(obj) // --> "{\"foo\":1}"
Valid JSON types are: objects, strings, numbers, arrays, true
, false
, and null
.
Some JSON resources:
How to POST JSON request using Apache HttpClient?
As mentioned in the excellent answer by janoside, you need to construct the JSON string and set it as a StringEntity
.
To construct the JSON string, you can use any library or method you are comfortable with. Jackson library is one easy example:
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.node.ObjectNode;
import org.apache.http.entity.ContentType;
import org.apache.http.entity.StringEntity;
ObjectMapper mapper = new ObjectMapper();
ObjectNode node = mapper.createObjectNode();
node.put("name", "value"); // repeat as needed
String JSON_STRING = node.toString();
postMethod.setEntity(new StringEntity(JSON_STRING, ContentType.APPLICATION_JSON));
Drop primary key using script in SQL Server database
The answer I got is that variables and subqueries
will not work and we have to user dynamic SQL script. The following works:
DECLARE @SQL VARCHAR(4000)
SET @SQL = 'ALTER TABLE dbo.Student DROP CONSTRAINT |ConstraintName| '
SET @SQL = REPLACE(@SQL, '|ConstraintName|', ( SELECT name
FROM sysobjects
WHERE xtype = 'PK'
AND parent_obj = OBJECT_ID('Student')))
EXEC (@SQL)
How to get week number in Python?
You can get the week number directly from datetime as string.
>>> import datetime
>>> datetime.date(2010, 6, 16).strftime("%V")
'24'
Also you can get different "types" of the week number of the year changing the strftime
parameter for:
%U
- Week number of the year (Sunday as the first day of the week) as a zero padded decimal number. All days in a new year preceding the first Sunday are considered to be in week 0. Examples: 00, 01, …, 53
%W
- Week number of the year (Monday as the first day of the week) as a decimal number. All days in a new year preceding the first Monday are considered to be in week 0. Examples: 00, 01, …, 53
[...]
(Added in Python 3.6, backported to some distribution's Python 2.7's) Several additional directives not required by the C89 standard are included for convenience. These parameters all correspond to ISO 8601 date values. These may not be available on all platforms when used with the strftime()
method.
[...]
%V
- ISO 8601 week as a decimal number with Monday as the first day of the week. Week 01 is the week containing Jan 4. Examples: 01, 02, …, 53
from: datetime — Basic date and time types — Python 3.7.3 documentation
I've found out about it from here. It worked for me in Python 2.7.6
Creating a copy of a database in PostgreSQL
Postgres allows the use of any existing database on the server as a template when creating a new database. I'm not sure whether pgAdmin gives you the option on the create database dialog but you should be able to execute the following in a query window if it doesn't:
CREATE DATABASE newdb WITH TEMPLATE originaldb OWNER dbuser;
Still, you may get:
ERROR: source database "originaldb" is being accessed by other users
To disconnect all other users from the database, you can use this query:
SELECT pg_terminate_backend(pg_stat_activity.pid) FROM pg_stat_activity
WHERE pg_stat_activity.datname = 'originaldb' AND pid <> pg_backend_pid();
Get user input from textarea
Remove the spaces around your =
:
<div>
<input type="text" [(ngModel)]="str" name="str">
</div>
But you need to have the variable named str
on back-end, than its should work fine.
GCC dump preprocessor defines
I usually do it this way:
$ gcc -dM -E - < /dev/null
Note that some preprocessor defines are dependent on command line options - you can test these by adding the relevant options to the above command line. For example, to see which SSE3/SSE4 options are enabled by default:
$ gcc -dM -E - < /dev/null | grep SSE[34]
#define __SSE3__ 1
#define __SSSE3__ 1
and then compare this when -msse4
is specified:
$ gcc -dM -E -msse4 - < /dev/null | grep SSE[34]
#define __SSE3__ 1
#define __SSE4_1__ 1
#define __SSE4_2__ 1
#define __SSSE3__ 1
Similarly you can see which options differ between two different sets of command line options, e.g. compare preprocessor defines for optimisation levels -O0
(none) and -O3
(full):
$ gcc -dM -E -O0 - < /dev/null > /tmp/O0.txt
$ gcc -dM -E -O3 - < /dev/null > /tmp/O3.txt
$ sdiff -s /tmp/O0.txt /tmp/O3.txt
#define __NO_INLINE__ 1 <
> #define __OPTIMIZE__ 1
Setting a div's height in HTML with CSS
This should work for you: Set the height to 100% in your css for the html
and body
elements. You can then adjust the height to your needs in the div
.
html {
height: 100%;
}
body {
height: 100%;
}
div {
height: 100%; /* Set Div Height */
}
POST request with JSON body
I made API sending data via form on website to prosperworks based on @Rocket Hazmat, @dbau and @maraca code.
I hope, it will help somebody:
<?php
if(isset($_POST['submit'])) {
//form's fields name:
$name = $_POST['nameField'];
$email = $_POST['emailField'];
//API url:
$url = 'https://api.prosperworks.com/developer_api/v1/leads';
//JSON data(not exact, but will be compiled to JSON) file:
//add as many data as you need (according to prosperworks doc):
$data = array(
'name' => $name,
'email' => array('email' => $email)
);
//sending request (according to prosperworks documentation):
// use key 'http' even if you send the request to https://...
$options = array(
'http' => array(
'header' => "Content-Type: application/json\r\n".
"X-PW-AccessToken: YOUR_TOKEN_HERE\r\n".
"X-PW-Application:developer_api\r\n".
"X-PW-UserEmail: YOUR_EMAIL_HERE\r\n",
'method' => 'POST',
'content' => json_encode($data)
)
);
//engine:
$context = stream_context_create($options);
$result = file_get_contents($url, false, $context);
if ($result === FALSE) { /* Handle error */ }
//compiling to JSON (as wrote above):
$resultData = json_decode($result, TRUE);
//display what was sent:
echo '<h2>Sent: </h2>';
echo $resultData['published'];
//dump var:
var_dump($result);
}
?>
<html>
<head>
</head>
<body>
<form action="" method="POST">
<h1><?php echo $msg; ?></h1>
Name: <input type="text" name="nameField"/>
<br>
Email: <input type="text" name="emailField"/>
<input type="submit" name="submit" value="Send"/>
</form>
</body>
</html>
How to rsync only a specific list of files?
I got similar task: to rsync all files modified after given date, but excluding some directories. It was difficult to build one liner all-in-one style, so I dived problem into smaller pieces.
Final solution:
find ~/sourceDIR -type f -newermt "DD MMM YYYY HH:MM:SS" | egrep -v "/\..|Downloads|FOO" > FileList.txt
rsync -v --files-from=FileList.txt ~/sourceDIR /Destination
First I use find -L ~/sourceDIR -type f -newermt "DD MMM YYYY HH:MM:SS"
. I tried to add regex
to find
line to exclude name patterns, however my flavor of Linux (Mint) seams not to understand negate regex in find
. Tried number of regex flavors - non work as desired.
So I end up with egrep -v
- option that excludes pattern easy way. My rsync
is not copying directories like /.cache or /.config plus some other I explicitly named.
URL Encode a string in jQuery for an AJAX request
encodeURIComponent works fine for me. we can give the url like this in ajax call.The code shown below:
$.ajax({
cache: false,
type: "POST",
url: "http://atandra.mivamerchantdev.com//mm5/json.mvc?Store_Code=ATA&Function=Module&Module_Code=thub_connector&Module_Function=THUB_Request",
data: "strChannelName=" + $('#txtupdstorename').val() + "&ServiceUrl=" + encodeURIComponent($('#txtupdserviceurl').val()),
dataType: "HTML",
success: function (data) {
},
error: function (xhr, ajaxOptions, thrownError) {
}
});
Long vs Integer, long vs int, what to use and when?
There are a couple of things you can't do with a primitive type:
- Have a
null
value
- synchronize on them
- Use them as type parameter for a generic class, and related to that:
- Pass them to an API that works with
Object
s
Unless you need any of those, you should prefer primitive types, since they require less memory.
Ruby - test for array
It sounds like you're after something that has some concept of items. I'd thus recommend seeing if it is Enumerable
. That also guarantees the existence of #count
.
For example,
[1,2,3].is_a? Enumerable
[1,2,3].count
note that, while size
, length
and count
all work for arrays, count
is the right meaning here - (for example, 'abc'.length
and 'abc'.size
both work, but 'abc'.count
doesn't work like that).
Caution: a string is_a? Enumerable, so perhaps this isn't what you want... depends on your concept of an array like object.
Inserting Data into Hive Table
You may try this, I have developed a tool to generate hive scripts from a csv file. Following are few examples on how files are generated.
Tool -- https://sourceforge.net/projects/csvtohive/?source=directory
Select a CSV file using Browse and set hadoop root directory ex: /user/bigdataproject/
Tool Generates Hadoop script with all csv files and following is a sample of
generated Hadoop script to insert csv into Hadoop
#!/bin/bash -v
hadoop fs -put ./AllstarFull.csv /user/bigdataproject/AllstarFull.csv
hive -f ./AllstarFull.hive
hadoop fs -put ./Appearances.csv /user/bigdataproject/Appearances.csv
hive -f ./Appearances.hive
hadoop fs -put ./AwardsManagers.csv /user/bigdataproject/AwardsManagers.csv
hive -f ./AwardsManagers.hive
Sample of generated Hive scripts
CREATE DATABASE IF NOT EXISTS lahman;
USE lahman;
CREATE TABLE AllstarFull (playerID string,yearID string,gameNum string,gameID string,teamID string,lgID string,GP string,startingPos string) row format delimited fields terminated by ',' stored as textfile;
LOAD DATA INPATH '/user/bigdataproject/AllstarFull.csv' OVERWRITE INTO TABLE AllstarFull;
SELECT * FROM AllstarFull;
Thanks
Vijay
pandas GroupBy columns with NaN (missing) values
I am not able to add a comment to M. Kiewisch since I do not have enough reputation points (only have 41 but need more than 50 to comment).
Anyway, just want to point out that M. Kiewisch solution does not work as is and may need more tweaking. Consider for example
>>> df = pd.DataFrame({'a': [1, 2, 3, 5], 'b': [4, np.NaN, 6, 4]})
>>> df
a b
0 1 4.0
1 2 NaN
2 3 6.0
3 5 4.0
>>> df.groupby(['b']).sum()
a
b
4.0 6
6.0 3
>>> df.astype(str).groupby(['b']).sum()
a
b
4.0 15
6.0 3
nan 2
which shows that for group b=4.0, the corresponding value is 15 instead of 6. Here it is just concatenating 1 and 5 as strings instead of adding it as numbers.
What is the maximum length of a valid email address?
user
The maximum total length of a user name is 64 characters.
domain
Maximum of 255 characters in the domain part (the one after the “@”)
However, there is a restriction in RFC 2821 reading:
The maximum total length of a reverse-path or forward-path is 256
characters, including the punctuation and element separators”. Since
addresses that don’t fit in those fields are not normally useful, the
upper limit on address lengths should normally be considered to be
256, but a path is defined as: Path = “<” [ A-d-l “:” ] Mailbox “>”
The forward-path will contain at least a pair of angle brackets in
addition to the Mailbox, which limits the email address to 254
characters.
FIFO class in Java
Not sure what you call FIFO these days since Queue is FILO, but when I was a student we used the Stack<E>
with the simple push, pop, and a peek... It is really that simple, no need for complicating further with Queue and whatever the accepted answer suggests.
How to check if a Constraint exists in Sql server?
SELECT tabla.name as Tabla,
restriccion.name as Restriccion,
restriccion.type as Tipo,
restriccion.type_desc as Tipo_Desc
FROM {DATABASE_NAME}.sys.objects tabla
INNER JOIN {DATABASE_NAME}.sys.objects restriccion
ON tabla.object_id = restriccion.parent_object_id
WHERE tabla.type = 'U' - Solo tablas creadas por el usuario.
AND restriccion.type = 'UQ' --Tipo de Restriccion UNIQUE
ORDER BY tabla.name, restriccion.type_desc
Convert Object to JSON string
Also useful is Object.toSource() for debugging purposes, where you want to show the object and its properties for debugging purposes. This is a generic Javascript (not jQuery) function, however it only works in "modern" browsers.
Display a table/list data dynamically in MVC3/Razor from a JsonResult?
You can do this easily with the KoGrid plugin for KnockoutJS.
<script type="text/javascript">
$(function () {
window.viewModel = {
myObsArray: ko.observableArray([
{ id: 1, firstName: 'John', lastName: 'Doe', createdOn: '1/1/2012', birthday: '1/1/1977', salary: 40000 },
{ id: 1, firstName: 'Jane', lastName: 'Harper', createdOn: '1/2/2012', birthday: '2/1/1976', salary: 45000 },
{ id: 1, firstName: 'Jim', lastName: 'Carrey', createdOn: '1/3/2012', birthday: '3/1/1985', salary: 60000 },
{ id: 1, firstName: 'Joe', lastName: 'DiMaggio', createdOn: '1/4/2012', birthday: '4/1/1991', salary: 70000 }
])
};
ko.applyBindings(viewModel);
});
</script>
<div data-bind="koGrid: { data: myObsArray }">
Sample
How do I get a list of all the duplicate items using pandas in python?
Using an element-wise logical or and setting the take_last argument of the pandas duplicated method to both True and False you can obtain a set from your dataframe that includes all of the duplicates.
df_bigdata_duplicates =
df_bigdata[df_bigdata.duplicated(cols='ID', take_last=False) |
df_bigdata.duplicated(cols='ID', take_last=True)
]
JSON.parse unexpected token s
Because JSON has a string data type (which is practically anything between "
and "
). It does not have a data type that matches something
self referential struct definition?
There is sort of a way around this:
struct Cell {
bool isParent;
struct Cell* child;
};
struct Cell;
typedef struct Cell Cell;
If you declare it like this, it properly tells the compiler that struct Cell and plain-ol'-cell are the same. So you can use Cell just like normal. Still have to use struct Cell inside of the initial declaration itself though.
Store select query's output in one array in postgres
There are two ways. One is to aggregate:
SELECT array_agg(column_name::TEXT)
FROM information.schema.columns
WHERE table_name = 'aean'
The other is to use an array constructor:
SELECT ARRAY(
SELECT column_name
FROM information.schema.columns
WHERE table_name = 'aean')
I'm presuming this is for plpgsql. In that case you can assign it like this:
colnames := ARRAY(
SELECT column_name
FROM information.schema.columns
WHERE table_name='aean'
);
Change the name of a key in dictionary
if you want to change all the keys:
d = {'x':1, 'y':2, 'z':3}
d1 = {'x':'a', 'y':'b', 'z':'c'}
In [10]: dict((d1[key], value) for (key, value) in d.items())
Out[10]: {'a': 1, 'b': 2, 'c': 3}
if you want to change single key:
You can go with any of the above suggestion.
Is it possible to use Visual Studio on macOS?
I recently purchased a MacBook Air (mid-2011 model) and was really happy to find that Apple officially supports Windows 7. If you purchase Windows 7 (I got DSP), you can use the Boot Camp assistant in OSX to designate part of your hard drive to Windows. Then you can install and run Windows 7 natively as if it were as Windows notebook.
I use Visual Studio 2010 on Windows 7 on my MacBook Air (I kept OSX as well) and I could not be happier. Heck, the initial start-up of the program only takes 3 seconds thanks to the SSD.
As others have mentions, you can run it on OSX using Parallels, etc. but I prefer to run it natively.
Catch an exception thrown by an async void method
The exception can be caught in the async function.
public async void Foo()
{
try
{
var x = await DoSomethingAsync();
/* Handle the result, but sometimes an exception might be thrown
For example, DoSomethingAsync get's data from the network
and the data is invalid... a ProtocolException might be thrown */
}
catch (ProtocolException ex)
{
/* The exception will be caught here */
}
}
public void DoFoo()
{
Foo();
}
Is there a concise way to iterate over a stream with indices in Java 8?
String[] namesArray = {"Sam","Pamela", "Dave", "Pascal", "Erik"};
String completeString
= IntStream.range(0,namesArray.length)
.mapToObj(i -> namesArray[i]) // Converting each array element into Object
.map(String::valueOf) // Converting object to String again
.collect(Collectors.joining(",")); // getting a Concat String of all values
System.out.println(completeString);
OUTPUT : Sam,Pamela,Dave,Pascal,Erik
String[] namesArray = {"Sam","Pamela", "Dave", "Pascal", "Erik"};
IntStream.range(0,namesArray.length)
.mapToObj(i -> namesArray[i]) // Converting each array element into Object
.map(String::valueOf) // Converting object to String again
.forEach(s -> {
//You can do various operation on each element here
System.out.println(s);
}); // getting a Concat String of all
To Collect in the List:
String[] namesArray = {"Sam","Pamela", "Dave", "Pascal", "Erik"};
List<String> namesList
= IntStream.range(0,namesArray.length)
.mapToObj(i -> namesArray[i]) // Converting each array element into Object
.map(String::valueOf) // Converting object to String again
.collect(Collectors.toList()); // collecting elements in List
System.out.println(listWithIndex);
java.sql.SQLException: No suitable driver found for jdbc:mysql://localhost:3306/dbname
All of the answers here use the Class.forName("my.vandor.Driver");
line to load the driver.
As an (better) alternative you can use the DriverManager
helper class which provides you with a handful of methods to handle your JDBC driver/s.
You might want to
- Use
DriverManager.registerDriver(driverObject);
to register your driver to it's list of drivers
Registers the given driver with the DriverManager. A newly-loaded driver class should call the method registerDriver to make itself known to the DriverManager. If the driver is currently registered, no action is taken
- Use
DriverManager.deregisterDriver(driverObject);
to remove it.
Removes the specified driver from the DriverManager's list of registered drivers.
Example:
Driver driver = new oracle.jdbc.OracleDriver();
DriverManager.registerDriver(driver);
Connection conn = DriverManager.getConnection(url, user, password);
// ...
// and when you don't need anything else from the driver
DriverManager.deregisterDriver(driver);
or better yet, use a DataSource
Inserting a tab character into text using C#
When using literal strings (start with @") this might be easier
char tab = '\u0009';
string A = "Apple";
string B = "Bob";
string myStr = String.Format(@"{0}:{1}{2}", A, tab, B);
Would result in Apple:<tab>Bob
Catch browser's "zoom" event in JavaScript
Lets define px_ratio as below:
px ratio = ratio of physical pixel to css px.
if any one zoom The Page, the viewport pxes (px is different from pixel ) reduces and should be fit to The screen so the ratio (physical pixel / CSS_px ) must get bigger.
but in window Resizing, screen size reduces as well as pxes. so the ratio will maintain.
zooming: trigger windows.resize event --> and change px_ratio
but
resizing: trigger windows.resize event --> doesn’t change px_ratio
//for zoom detection
px_ratio = window.devicePixelRatio || window.screen.availWidth / document.documentElement.clientWidth;
$(window).resize(function(){isZooming();});
function isZooming(){
var newPx_ratio = window.devicePixelRatio || window.screen.availWidth / document.documentElement.clientWidth;
if(newPx_ratio != px_ratio){
px_ratio = newPx_ratio;
console.log("zooming");
return true;
}else{
console.log("just resizing");
return false;
}
}
The key point is difference between CSS PX and Physical Pixel.
https://gist.github.com/abilogos/66aba96bb0fb27ab3ed4a13245817d1e
Getting Serial Port Information
this.comboPortName.Items.AddRange(
(from qP in System.IO.Ports.SerialPort.GetPortNames()
orderby System.Text.RegularExpressions.Regex.Replace(qP, "~\\d",
string.Empty).PadLeft(6, '0')
select qP).ToArray()
);
Hiding an Excel worksheet with VBA
You can do this programmatically using a VBA macro. You can make the sheet hidden or very hidden:
Sub HideSheet()
Dim sheet As Worksheet
Set sheet = ActiveSheet
' this hides the sheet but users will be able
' to unhide it using the Excel UI
sheet.Visible = xlSheetHidden
' this hides the sheet so that it can only be made visible using VBA
sheet.Visible = xlSheetVeryHidden
End Sub
WPF Check box: Check changed handling
As a checkbox click = a checkbox change the following will also work:
<CheckBox Click="CheckBox_Click" />
private void CheckBox_Click(object sender, RoutedEventArgs e)
{
// ... do some stuff
}
It has the additional advantage of working when IsThreeState="True"
whereas just handling Checked and Unchecked does not.
Simple and fast method to compare images for similarity
If you can be sure to have precise alignment of your template (the icon) to the testing region, then any old sum of pixel differences will work.
If the alignment is only going to be a tiny bit off, then you can low-pass both images with cv::GaussianBlur before finding the sum of pixel differences.
If the quality of the alignment is potentially poor then I would recommend either a Histogram of Oriented Gradients or one of OpenCV's convenient keypoint detection/descriptor algorithms (such as SIFT or SURF).
How to vertical align an inline-block in a line of text?
display: inline-block
is your friend you just need all three parts of the construct - before, the "block", after - to be one, then you can vertically align them all to the middle:
(it looks like your picture anyway ;))
CSS:
p, div {
display: inline-block;
vertical-align: middle;
}
p, div {
display: inline !ie7; /* hack for IE7 and below */
}
table {
background: #000;
color: #fff;
font-size: 16px;
font-weight: bold; margin: 0 10px;
}
td {
padding: 5px;
text-align: center;
}
HTML:
<p>some text</p>
<div>
<table summary="">
<tr><td>A</td></tr>
<tr><td>B</td></tr>
<tr><td>C</td></tr>
<tr><td>D</td></tr>
</table>
</div>
<p>continues afterwards</p>
How to read keyboard-input?
Non-blocking, multi-threaded example:
As blocking on keyboard input (since the input()
function blocks) is frequently not what we want to do (we'd frequently like to keep doing other stuff), here's a very-stripped-down multi-threaded example to demonstrate how to keep running your main application while still reading in keyboard inputs whenever they arrive.
This works by creating one thread to run in the background, continually calling input()
and then passing any data it receives to a queue.
In this way, your main thread is left to do anything it wants, receiving the keyboard input data from the first thread whenever there is something in the queue.
1. Bare Python 3 code example (no comments):
import threading
import queue
import time
def read_kbd_input(inputQueue):
print('Ready for keyboard input:')
while (True):
input_str = input()
inputQueue.put(input_str)
def main():
EXIT_COMMAND = "exit"
inputQueue = queue.Queue()
inputThread = threading.Thread(target=read_kbd_input, args=(inputQueue,), daemon=True)
inputThread.start()
while (True):
if (inputQueue.qsize() > 0):
input_str = inputQueue.get()
print("input_str = {}".format(input_str))
if (input_str == EXIT_COMMAND):
print("Exiting serial terminal.")
break
# Insert your code here to do whatever you want with the input_str.
# The rest of your program goes here.
time.sleep(0.01)
print("End.")
if (__name__ == '__main__'):
main()
2. Same Python 3 code as above, but with extensive explanatory comments:
"""
read_keyboard_input.py
Gabriel Staples
www.ElectricRCAircraftGuy.com
14 Nov. 2018
References:
- https://pyserial.readthedocs.io/en/latest/pyserial_api.html
- *****https://www.tutorialspoint.com/python/python_multithreading.htm
- *****https://en.wikibooks.org/wiki/Python_Programming/Threading
- https://stackoverflow.com/questions/1607612/python-how-do-i-make-a-subclass-from-a-superclass
- https://docs.python.org/3/library/queue.html
- https://docs.python.org/3.7/library/threading.html
To install PySerial: `sudo python3 -m pip install pyserial`
To run this program: `python3 this_filename.py`
"""
import threading
import queue
import time
def read_kbd_input(inputQueue):
print('Ready for keyboard input:')
while (True):
# Receive keyboard input from user.
input_str = input()
# Enqueue this input string.
# Note: Lock not required here since we are only calling a single Queue method, not a sequence of them
# which would otherwise need to be treated as one atomic operation.
inputQueue.put(input_str)
def main():
EXIT_COMMAND = "exit" # Command to exit this program
# The following threading lock is required only if you need to enforce atomic access to a chunk of multiple queue
# method calls in a row. Use this if you have such a need, as follows:
# 1. Pass queueLock as an input parameter to whichever function requires it.
# 2. Call queueLock.acquire() to obtain the lock.
# 3. Do your series of queue calls which need to be treated as one big atomic operation, such as calling
# inputQueue.qsize(), followed by inputQueue.put(), for example.
# 4. Call queueLock.release() to release the lock.
# queueLock = threading.Lock()
#Keyboard input queue to pass data from the thread reading the keyboard inputs to the main thread.
inputQueue = queue.Queue()
# Create & start a thread to read keyboard inputs.
# Set daemon to True to auto-kill this thread when all other non-daemonic threads are exited. This is desired since
# this thread has no cleanup to do, which would otherwise require a more graceful approach to clean up then exit.
inputThread = threading.Thread(target=read_kbd_input, args=(inputQueue,), daemon=True)
inputThread.start()
# Main loop
while (True):
# Read keyboard inputs
# Note: if this queue were being read in multiple places we would need to use the queueLock above to ensure
# multi-method-call atomic access. Since this is the only place we are removing from the queue, however, in this
# example program, no locks are required.
if (inputQueue.qsize() > 0):
input_str = inputQueue.get()
print("input_str = {}".format(input_str))
if (input_str == EXIT_COMMAND):
print("Exiting serial terminal.")
break # exit the while loop
# Insert your code here to do whatever you want with the input_str.
# The rest of your program goes here.
# Sleep for a short time to prevent this thread from sucking up all of your CPU resources on your PC.
time.sleep(0.01)
print("End.")
# If you run this Python file directly (ex: via `python3 this_filename.py`), do the following:
if (__name__ == '__main__'):
main()
Sample output:
$ python3 read_keyboard_input.py
Ready for keyboard input:
hey
input_str = hey
hello
input_str = hello
7000
input_str = 7000
exit
input_str = exit
Exiting serial terminal.
End.
The Python Queue library is thread-safe:
Note that Queue.put()
and Queue.get()
and other Queue class methods are thread-safe! That means they implement all the internal locking semantics required for inter-thread operations, so each function call in the queue class can be considered as a single, atomic operation. See the notes at the top of the documentation: https://docs.python.org/3/library/queue.html (emphasis added):
The queue module implements multi-producer, multi-consumer queues. It is especially useful in threaded programming when information must be exchanged safely between multiple threads. The Queue class in this module implements all the required locking semantics.
References:
- https://pyserial.readthedocs.io/en/latest/pyserial_api.html
- *****https://www.tutorialspoint.com/python/python_multithreading.htm
- *****https://en.wikibooks.org/wiki/Python_Programming/Threading
- Python: How do I make a subclass from a superclass?
- https://docs.python.org/3/library/queue.html
- https://docs.python.org/3.7/library/threading.html
Related/Cross-Linked:
- PySerial non-blocking read loop
How to check if a text field is empty or not in swift
I just tried to show you the solution in a simple code
@IBAction func Button(sender : AnyObject) {
if textField1.text != "" {
// either textfield 1 is not empty then do this task
}else{
//show error here that textfield1 is empty
}
}
What does 'git blame' do?
The git blame
command annotates lines with information from the revision which last modified the line, and... with Git 2.22 (Q2 2019), will do so faster, because of a performance fix around "git blame
", especially in a linear history (which is the norm we should optimize for).
See commit f892014 (02 Apr 2019) by David Kastrup (fedelibre
).
(Merged by Junio C Hamano -- gitster
-- in commit 4d8c4da, 25 Apr 2019)
blame.c
: don't drop origin blobs as eagerly
When a parent blob already has chunks queued up for blaming, dropping the blob at the end of one blame step will cause it to get reloaded right away, doubling the amount of I/O and unpacking when processing a linear history.
Keeping such parent blobs in memory seems like a reasonable optimization that should incur additional memory pressure mostly when processing the merges from old branches.
How do you fadeIn and animate at the same time?
Another way to do simultaneous animations if you want to call them separately (eg. from different code) is to use queue
. Again, as with Tinister's answer you would have to use animate for this and not fadeIn:
$('.tooltip').css('opacity', 0);
$('.tooltip').show();
...
$('.tooltip').animate({opacity: 1}, {queue: false, duration: 'slow'});
$('.tooltip').animate({ top: "-10px" }, 'slow');
How to compare data between two table in different databases using Sql Server 2008?
Comparing the two Databases in SQL Database. Try this Query it may help.
SELECT T.[name] AS [table_name], AC.[name] AS [column_name], TY.[name] AS
system_data_type FROM [***Database Name 1***].sys.[tables] AS T
INNER JOIN [***Database Name 1***].sys.[all_columns] AC ON T.[object_id] = AC.[object_id]
INNER JOIN [***Database Name 1***].sys.[types] TY ON AC.[system_type_id] = TY.[system_type_id]
EXCEPT SELECT T.[name] AS [table_name], AC.[name] AS [column_name], TY.[name] AS system_data_type FROM ***Database Name 2***.sys.[tables] AS T
INNER JOIN ***Database Name 2***.sys.[all_columns] AC ON T.[object_id] = AC.[object_id]
INNER JOIN ***Database Name 2***.sys.[types] TY ON AC.[system_type_id] = TY.[system_type_id]
What is System, out, println in System.out.println() in Java
Whenever you're confused, I would suggest consulting the Javadoc as the first place for your clarification.
From the javadoc about System
, here's what the doc says:
public final class System
extends Object
The System class contains several useful class fields and methods. It cannot be instantiated.
Among the facilities provided by the System class are standard input, standard output, and error output streams; access to externally defined properties and environment variables; a means of loading files and libraries; and a utility method for quickly copying a portion of an array.
Since:
JDK1.0
Regarding System.out
public static final PrintStream out
The "standard" output stream. This stream is already open and ready to accept output data. Typically this stream corresponds to display output or another output destination specified by the host environment or user.
For simple stand-alone Java applications, a typical way to write a line of output data is:
System.out.println(data)
How to call a method in another class in Java?
You should capitalize names of your classes. After doing that do this in your school class,
Classroom cls = new Classroom();
cls.setTeacherName(newTeacherName);
Also I'd recommend you use some kind of IDE such as eclipse, which can help you with your code for instance generate getters and setters for you. Ex: right click Source -> Generate getters and setters
Read XLSX file in Java
Try this:
- Unzip XLSX file
- Read XML files
- Compose and use data
Example code:
public Workbook getTemplateData(String xlsxFile) {
Workbook workbook = new Workbook();
parseSharedStrings(xlsxFile);
parseWorkesheet(xlsxFile, workbook);
parseComments(xlsxFile, workbook);
for (Worksheet worksheet : workbook.sheets) {
worksheet.dimension = manager.getDimension(worksheet);
}
return workbook;
}
private void parseComments(String tmpFile, Workbook workbook) {
try {
FileInputStream fin = new FileInputStream(tmpFile);
final ZipInputStream zin = new ZipInputStream(fin);
InputStream in = getInputStream(zin);
while (true) {
ZipEntry entry = zin.getNextEntry();
if (entry == null)
break;
String name = entry.getName();
if (name.endsWith(".xml")) { //$NON-NLS-1$
if (name.contains(COMMENTS)) {
parseComments(in, workbook);
}
}
zin.closeEntry();
}
in.close();
zin.close();
fin.close();
} catch (FileNotFoundException e) {
System.out.println(e);
} catch (IOException e) {
e.printStackTrace();
}
}
private void parseComments(InputStream in, Workbook workbook) {
try {
DefaultHandler handler = getCommentHandler(workbook);
SAXParser saxParser = getSAXParser();
saxParser.parse(in, handler);
} catch (Exception e) {
e.printStackTrace();
}
}
private DefaultHandler getCommentHandler(Workbook workbook) {
final Worksheet ws = workbook.sheets.get(0);
return new DefaultHandler() {
String lastTag = "";
private Cell ccell;
@Override
public void startElement(String uri, String localName,
String qName, Attributes attributes) throws SAXException {
lastTag = qName;
if (lastTag.equals("comment")) {
String cellName = attributes.getValue("ref");
int r = manager.getRowIndex(cellName);
int c = manager.getColumnIndex(cellName);
Row row = ws.rows.get(r);
if (row == null) {
row = new Row();
row.index = r;
ws.rows.put(r, row);
}
ccell = row.cells.get(c);
if (ccell == null) {
ccell = new Cell();
ccell.cellName = cellName;
row.cells.put(c, ccell);
}
}
}
@Override
public void characters(char[] ch, int start, int length)
throws SAXException {
String val = "";
if (ccell != null && lastTag.equals("t")) {
for (int i = start; i < start + length; i++) {
val += ch[i];
}
if (ccell.comment == null)
ccell.comment = val;
else {
ccell.comment += val;
}
}
}
};
}
private void parseSharedStrings(String tmpFile) {
try {
FileInputStream fin = new FileInputStream(tmpFile);
final ZipInputStream zin = new ZipInputStream(fin);
InputStream in = getInputStream(zin);
while (true) {
ZipEntry entry = zin.getNextEntry();
if (entry == null)
break;
String name = entry.getName();
if (name.endsWith(".xml")) { //$NON-NLS-1$
if (name.startsWith(SHARED_STRINGS)) {
parseStrings(in);
}
}
zin.closeEntry();
}
in.close();
zin.close();
fin.close();
} catch (FileNotFoundException e) {
System.out.println(e);
} catch (IOException e) {
e.printStackTrace();
}
}
public void parseWorkesheet(String tmpFile, Workbook workbook) {
try {
FileInputStream fin = new FileInputStream(tmpFile);
final ZipInputStream zin = new ZipInputStream(fin);
InputStream in = getInputStream(zin);
while (true) {
ZipEntry entry = zin.getNextEntry();
if (entry == null)
break;
String name = entry.getName();
if (name.endsWith(".xml")) { //$NON-NLS-1$
if (name.contains("worksheets")) {
Worksheet worksheet = new Worksheet();
worksheet.name = name;
parseWorksheet(in, worksheet);
workbook.sheets.add(worksheet);
}
}
zin.closeEntry();
}
in.close();
zin.close();
fin.close();
} catch (FileNotFoundException e) {
System.out.println(e);
} catch (IOException e) {
e.printStackTrace();
}
}
public void parseWorksheet(InputStream in, Worksheet worksheet)
throws IOException {
// read sheet1 sharedStrings
// styles, strings, formulas ...
try {
DefaultHandler handler = getDefaultHandler(worksheet);
SAXParser saxParser = getSAXParser();
saxParser.parse(in, handler);
} catch (SAXException e) {
e.printStackTrace();
} catch (ParserConfigurationException e) {
e.printStackTrace();
}
}
where Workbook class:
public class Workbook {
Integer id = null;
public List<Worksheet> sheets = new ArrayList<Worksheet>();}
and Worksheet class:
public class Worksheet {
public Integer id = null;
public String name = null;
public String dimension = null;
public Map<Integer, Row> rows = new TreeMap<Integer, Row>();
public Map<Integer, Column> columns = new TreeMap<Integer, Column>();
public List<Span> spans = new ArrayList<Span>();}
and Row class:
public class Row {
public Integer id = null;
public Integer index = null;
public Row tmpRow = null;
public Style style = null;
public Double height = null;
public Map<Integer,Cell> cells = new TreeMap<Integer, Cell>();
public String spans = null;
public Integer customHeight = null;}
and Cell class:
public class Cell {
public Integer id = null;
public Integer rowIndex = null;
public Integer colIndex = null;
public String cellName = null;
public String text = null;
public String formula = null;
public String comment = null;
public Style style = null;
public Object value = null;
public Cell tmpCell = null;}
and Column class:
public class Column {
public Integer index = null;
public Style style = null;
public String width = null;
public Column tmpColumn = null;
}
and Span class:
public class Span {
Integer id = null;
String topLeft = null;
String bottomRight = null;
}
Razor Views not seeing System.Web.Mvc.HtmlHelper
As for me, it was a stupid deployment mistake: Web projects can have more than one web.config. It was working on the developer's machine and not in production, but we were not realising that the deployment script only grabbed the Web.config
file at the root, and it didn't copy the Web.config
file in the Views
folder.
favicon.png vs favicon.ico - why should I use PNG instead of ICO?
For what it's worth, I do this:
<!-- Favicon - Generic -->
<link rel="icon" href="path/favicon-32_x_32.png" sizes="32x32">
<link rel="icon" href="path/favicon-57_x_57.png" sizes="57x57">
<link rel="icon" href="path/favicon-76_x_76.png" sizes="76x76">
<link rel="icon" href="path/favicon-96_x_96.png" sizes="96x96">
<link rel="icon" href="path/favicon-128_x_128.png" sizes="128x128">
<link rel="icon" href="path/favicon-192_x_192.png" sizes="192x192">
<link rel="icon" href="path/favicon-228_x_228.png" sizes="228x228">
<!-- Favicon - Android -->
<link rel="shortcut icon" href="path/favicon-196_x_196.png" sizes="196x196">
<!-- Favicon - iOS -->
<link rel="apple-touch-icon" href="path/favicon-120_x_120.png" sizes="120x120">
<link rel="apple-touch-icon" href="path/favicon-152_x_152.png" sizes="152x152">
<link rel="apple-touch-icon" href="path/favicon-180_x_180.png" sizes="180x180">
And I still keep the favicon.ico in root.
How to bind a List to a ComboBox?
Try something like this:
yourControl.DataSource = countryInstance.Cities;
And if you are using WebForms you will need to add this line:
yourControl.DataBind();
The specified child already has a parent. You must call removeView() on the child's parent first
In my case the problem was I was trying to add same view multiple times to linear layout
View childView = LayoutInflater.from(context).inflate(R.layout.lay_progressheader, parentLayout,false);
for (int i = 1; i <= totalCount; i++) {
parentLayout.addView(childView);
}
just initialize view every time to fix the issue
for (int i = 1; i <= totalCount; i++) {
View childView = LayoutInflater.from(context).inflate(R.layout.lay_progressheader, parentLayout,false);
parentLayout.addView(childView);
}
Why have header files and .cpp files?
Because in C++, the final executable code does not carry any symbol information, it's more or less pure machine code.
Thus, you need a way to describe the interface of a piece of code, that is separate from the code itself. This description is in the header file.
What's the best way to calculate the size of a directory in .NET?
The real question is, what do you intend to use the size for?
Your first problem is that there are at least four definitions for "file size":
The "end of file" offset, which is the number of bytes you have to skip to go from the beginning to the end of the file.
In other words, it is the number of bytes logically in the file (from a usage perspective).
The "valid data length", which is equal to the offset of the first byte which is not actually stored.
This is always less than or equal to the "end of file", and is a multiple of the cluster size.
For example, a 1 GB file can have a valid data length of 1 MB. If you ask Windows to read the first 8 MB, it will read the first 1 MB and pretend the rest of the data was there, returning it as zeros.
The "allocated size" of a file. This is always greater than or equal to the "end of file".
This is the number of clusters that the OS has allocated for the file, multiplied by the cluster size.
Unlike the case where the "end of file" is greater than the "valid data length", The excess bytes are not considered to be part of the file's data, so the OS will not fill a buffer with zeros if you try to read in the allocated region beyond the end of the file.
The "compressed size" of a file, which is only valid for compressed (and sparse?) files.
It is equal to the size of a cluster, multiplied by the number of clusters on the volume that are actually allocated to this file.
For non-compressed and non-sparse files, there is no notion of "compressed size"; you would use the "allocated size" instead.
Your second problem is that a "file" like C:\Foo
can actually have multiple streams of data.
This name just refers to the default stream. A file might have alternate streams, like C:\Foo:Bar
, whose size is not even shown in Explorer!
Your third problem is that a "file" can have multiple names ("hard links").
For example, C:\Windows\notepad.exe
and C:\Windows\System32\notepad.exe
are two names for the same file. Any name can be used to open any stream of the file.
Your fourth problem is that a "file" (or directory) might in fact not even be a file (or directory):
It might be a soft link (a "symbolic link" or a "reparse point") to some other file (or directory).
That other file might not even be on the same drive. It might even point to something on the network, or it might even be recursive! Should the size be infinity if it's recursive?
Your fifth is that there are "filter" drivers that make certain files or directories look like actual files or directories, even though they aren't. For example, Microsoft's WIM image files (which are compressed) can be "mounted" on a folder using a tool called ImageX, and those do not look like reparse points or links. They look just like directories -- except that the're not actually directories, and the notion of "size" doesn't really make sense for them.
Your sixth problem is that every file requires metadata.
For example, having 10 names for the same file requires more metadata, which requires space. If the file names are short, having 10 names might be as cheap as having 1 name -- and if they're long, then having multiple names can use more disk space for the metadata. (Same story with multiple streams, etc.)
Do you count these, too?
bash "if [ false ];" returns true instead of false -- why?
as noted by @tripleee, this is tangential, at best.
still, in case you arrived here searching for something like that (as i did), here is my solution
having to deal with user acessible configuration files, i use this function :
function isTrue() {
if [[ "${@^^}" =~ ^(TRUE|OUI|Y|O$|ON$|[1-9]) ]]; then return 0;fi
return 1
}
wich can be used like that
if isTrue "$whatever"; then..
You can alter the "truth list" in the regexp, the one in this sample is french compatible and considers strings like "Yeah, yup, on,1, Oui,y,true to be "True".
note that the '^^' provides case insensivity
How do you make strings "XML safe"?
Try this:
$str = htmlentities($str,ENT_QUOTES,'UTF-8');
So, after filtering your data using htmlentities()
function, you can use the data in XML tag like:
<mytag>$str</mytag>
What is a daemon thread in Java?
All the above answers are good. Here's a simple little code snippet, to illustrate the difference. Try it with each of the values of true and false in setDaemon
.
public class DaemonTest {
public static void main(String[] args) {
new WorkerThread().start();
try {
Thread.sleep(7500);
} catch (InterruptedException e) {
// handle here exception
}
System.out.println("Main Thread ending") ;
}
}
class WorkerThread extends Thread {
public WorkerThread() {
// When false, (i.e. when it's a non daemon thread),
// the WorkerThread continues to run.
// When true, (i.e. when it's a daemon thread),
// the WorkerThread terminates when the main
// thread or/and user defined thread(non daemon) terminates.
setDaemon(true);
}
public void run() {
int count = 0;
while (true) {
System.out.println("Hello from Worker "+count++);
try {
sleep(5000);
} catch (InterruptedException e) {
// handle exception here
}
}
}
}
How to install pip in CentOS 7?
Below are the steps I followed to install python34 and pip
yum update -y
yum -y install yum-utils
yum -y groupinstall development
yum -y install https://centos7.iuscommunity.org/ius-release.rpm
yum makecache
yum -y install python34u python34u-pip
python3.6 -v
echo "alias python=/usr/bin/python3.4" >> ~/.bash_profile
source ~/.bash_profile
pip3 install --upgrade pip
# if yum install python34u-pip doesnt work, try
curl https://bootstrap.pypa.io/get-pip.py | python
How to print in C
In C, unlike say C++, you would need a format specifier that states the datatype of the variable you want to print-in this case %d as the data type is an integer .
Try printf("%d",addNumbers(a,b));
Javadoc link to method in other class
So the solution to the original problem is that you don't need both the "@see" and the "{@link...}" references on the same line. The "@link" tag is self-sufficient and, as noted, you can put it anywhere in the javadoc block. So you can mix the two approaches:
/**
* some javadoc stuff
* {@link com.my.package.Class#method()}
* more stuff
* @see com.my.package.AnotherClass
*/
How do I calculate the MD5 checksum of a file in Python?
In Python 3.8+ you can do
import hashlib
with open("your_filename.png", "rb") as f:
file_hash = hashlib.md5()
while chunk := f.read(8192):
file_hash.update(chunk)
print(file_hash.digest())
print(file_hash.hexdigest()) # to get a printable str instead of bytes
On Python 3.7 and below:
with open("your_filename.png", "rb") as f:
file_hash = hashlib.md5()
chunk = f.read(8192)
while chunk:
file_hash.update(chunk)
chunk = f.read(8192)
print(file_hash.hexdigest())
This reads the file 8192 (or 2¹³) bytes at a time instead of all at once with f.read()
to use less memory.
Consider using hashlib.blake2b
instead of md5
(just replace md5
with blake2b
in the above snippets). It's cryptographically secure and faster than MD5.
Encode a FileStream to base64 with c#
A simple Stream extension method would do the job:
public static class StreamExtensions
{
public static string ConvertToBase64(this Stream stream)
{
var bytes = new Byte[(int)stream.Length];
stream.Seek(0, SeekOrigin.Begin);
stream.Read(bytes, 0, (int)stream.Length);
return Convert.ToBase64String(bytes);
}
}
The methods for Read (and also Write) and optimized for the respective class (whether is file stream, memory stream, etc.) and will do the work for you. For simple task like this, there is no need of readers, and etc.
The only drawback is that the stream is copied into byte array, but that is how the conversion to base64 via Convert.ToBase64String works unfortunately.
Disable/Enable Submit Button until all forms have been filled
I think this will be much simpler for beginners in JavaScript
//The function checks if the password and confirm password match
// Then disables the submit button for mismatch but enables if they match
function checkPass()
{
//Store the password field objects into variables ...
var pass1 = document.getElementById("register-password");
var pass2 = document.getElementById("confirm-password");
//Store the Confimation Message Object ...
var message = document.getElementById('confirmMessage');
//Set the colors we will be using ...
var goodColor = "#66cc66";
var badColor = "#ff6666";
//Compare the values in the password field
//and the confirmation field
if(pass1.value == pass2.value){
//The passwords match.
//Set the color to the good color and inform
//the user that they have entered the correct password
pass2.style.backgroundColor = goodColor;
message.style.color = goodColor;
message.innerHTML = "Passwords Match!"
//Enables the submit button when there's no mismatch
var tabPom = document.getElementById("btnSignUp");
$(tabPom ).prop('disabled', false);
}else{
//The passwords do not match.
//Set the color to the bad color and
//notify the user.
pass2.style.backgroundColor = badColor;
message.style.color = badColor;
message.innerHTML = "Passwords Do Not Match!"
//Disables the submit button when there's mismatch
var tabPom = document.getElementById("btnSignUp");
$(tabPom ).prop('disabled', true);
}
}
Remove element from JSON Object
JSfiddle
function deleteEmpty(obj){
for(var k in obj)
if(k == "children"){
if(obj[k]){
deleteEmpty(obj[k]);
}else{
delete obj.children;
}
}
}
for(var i=0; i< a.children.length; i++){
deleteEmpty(a.children[i])
}
Get current working directory in a Qt application
Thank you RedX and Kaz for your answers. I don't get why by me it gives the path of the exe. I found an other way to do it :
QString pwd("");
char * PWD;
PWD = getenv ("PWD");
pwd.append(PWD);
cout << "Working directory : " << pwd << flush;
It is less elegant than a single line... but it works for me.
Strange PostgreSQL "value too long for type character varying(500)"
By specifying the column as VARCHAR(500)
you've set an explicit 500 character limit. You might not have done this yourself explicitly, but Django has done it for you somewhere. Telling you where is hard when you haven't shown your model, the full error text, or the query that produced the error.
If you don't want one, use an unqualified VARCHAR
, or use the TEXT
type.
varchar
and text
are limited in length only by the system limits on column size - about 1GB - and by your memory. However, adding a length-qualifier to varchar
sets a smaller limit manually. All of the following are largely equivalent:
column_name VARCHAR(500)
column_name VARCHAR CHECK (length(column_name) <= 500)
column_name TEXT CHECK (length(column_name) <= 500)
The only differences are in how database metadata is reported and which SQLSTATE is raised when the constraint is violated.
The length constraint is not generally obeyed in prepared statement parameters, function calls, etc, as shown:
regress=> \x
Expanded display is on.
regress=> PREPARE t2(varchar(500)) AS SELECT $1;
PREPARE
regress=> EXECUTE t2( repeat('x',601) );
-[ RECORD 1 ]-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
?column? | xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
and in explicit casts it result in truncation:
regress=> SELECT repeat('x',501)::varchar(1);
-[ RECORD 1 ]
repeat | x
so I think you are using a VARCHAR(500)
column, and you're looking at the wrong table or wrong instance of the database.
In angular $http service, How can I catch the "status" of error?
Since $http.get
returns a 'promise' with the extra convenience methods success
and error
(which just wrap the result of then
) you should be able to use (regardless of your Angular version):
$http.get('/someUrl')
.then(function success(response) {
console.log('succeeded', response); // supposed to have: data, status, headers, config, statusText
}, function error(response) {
console.log('failed', response); // supposed to have: data, status, headers, config, statusText
})
Not strictly an answer to the question, but if you're getting bitten by the "my version of Angular is different than the docs" issue you can always dump all of the arguments
, even if you don't know the appropriate method signature:
$http.get('/someUrl')
.success(function(data, foo, bar) {
console.log(arguments); // includes data, status, etc including unlisted ones if present
})
.error(function(baz, foo, bar, idontknow) {
console.log(arguments); // includes data, status, etc including unlisted ones if present
});
Then, based on whatever you find, you can 'fix' the function arguments to match.
Content Type text/xml; charset=utf-8 was not supported by service
I was also facing the same problem recently. after struggling a couple of hours,finally a solution came out by addition to
Factory="System.ServiceModel.Activation.WebServiceHostFactory"
to your SVC markup file. e.g.
ServiceHost Language="C#" Debug="true" Service="QuiznetOnline.Web.UI.WebServices.LogService"
Factory="System.ServiceModel.Activation.WebServiceHostFactory"
and now you can compile & run your application successfully.
Get the current cell in Excel VB
I realize this doesn't directly apply from the title of the question, However some ways to deal with a variable range could be to select the range each time the code runs -- especially if you are interested in a user-selected range. If you are interested in that option, you can use the Application.InputBox (official documentation page here). One of the optional variables is 'type'. If the type is set equal to 8, the InputBox also has an excel-style range selection option. An example of how to use it in code would be:
Dim rng as Range
Set rng = Application.InputBox(Prompt:= "Please select a range", Type:=8)
Note:
If you assign the InputBox value to a none-range variable (without the Set
keyword), instead of the ranges, the values from the ranges will be assigned, as in the code below (although selecting multiple ranges in this situation may require the values to be assigned to a variant):
Dim str as String
str = Application.InputBox(Prompt:= "Please select a range", Type:=8)
Add querystring parameters to link_to
If you want to keep existing params and not expose yourself to XSS attacks, be sure to clean the params hash, leaving only the params that your app can be sending:
# inline
<%= link_to 'Link', params.slice(:sort).merge(per_page: 20) %>
If you use it in multiple places, clean the params in the controller:
# your_controller.rb
@params = params.slice(:sort, :per_page)
# view
<%= link_to 'Link', @params.merge(per_page: 20) %>
Jquery Setting Value of Input Field
use this code for set value in input tag by another id.
$(".formdata").val(document.getElementById("fsd").innerHTML);
or
use this code for set value in input tag using classname="formdata"
$(".formdata").val("hello");
Find the most frequent number in a NumPy array
Performances (using iPython) for some solutions found here:
>>> # small array
>>> a = [12,3,65,33,12,3,123,888000]
>>>
>>> import collections
>>> collections.Counter(a).most_common()[0][0]
3
>>> %timeit collections.Counter(a).most_common()[0][0]
100000 loops, best of 3: 11.3 µs per loop
>>>
>>> import numpy
>>> numpy.bincount(a).argmax()
3
>>> %timeit numpy.bincount(a).argmax()
100 loops, best of 3: 2.84 ms per loop
>>>
>>> import scipy.stats
>>> scipy.stats.mode(a)[0][0]
3.0
>>> %timeit scipy.stats.mode(a)[0][0]
10000 loops, best of 3: 172 µs per loop
>>>
>>> from collections import defaultdict
>>> def jjc(l):
... d = defaultdict(int)
... for i in a:
... d[i] += 1
... return sorted(d.iteritems(), key=lambda x: x[1], reverse=True)[0]
...
>>> jjc(a)[0]
3
>>> %timeit jjc(a)[0]
100000 loops, best of 3: 5.58 µs per loop
>>>
>>> max(map(lambda val: (a.count(val), val), set(a)))[1]
12
>>> %timeit max(map(lambda val: (a.count(val), val), set(a)))[1]
100000 loops, best of 3: 4.11 µs per loop
>>>
Best is 'max' with 'set' for small arrays like the problem.
According to @David Sanders, if you increase the array size to something like 100,000 elements, the "max w/set" algorithm ends up being the worst by far whereas the "numpy bincount" method is the best.
How can I increase the size of a bootstrap button?
bootstrap comes with clas btn-lg
http://getbootstrap.com/components/#btn-dropdowns-sizing
<div class="btn btn-default btn-block">
Active
</div>
but if you want to have the button of the width of your column / container add btn-block
<div class="btn btn-default btn-lg">
Active
</div>
However this will expand to 100% so make surt ethat you will wrap your button in certain amount of columns e.g. then you know its always stays 3 columns until xs screen
<div class="col-sm-3">
<div class="btn btn-default btn-block">
Active
</div>
</div>
Is there a way to create key-value pairs in Bash script?
In bash, we use
declare -A name_of_dictonary_variable
so that Bash understands it is a dictionary.
For e.g. you want to create sounds
dictionary then,
declare -A sounds
sounds[dog]="Bark"
sounds[wolf]="Howl"
where dog
and wolf
are "keys"
, and Bark
and Howl
are "values"
.
You can access all values using : echo ${sounds[@]}
OR echo ${sounds[*]}
You can access all keys only using: echo ${!sounds[@]}
And if you want any value for a particular key, you can use:
${sounds[dog]}
this will give you value (Bark
) for key (Dog
).
Fancybox doesn't work with jQuery v1.9.0 [ f.browser is undefined / Cannot read property 'msie' ]
In case anyone still has to support legacy fancybox with jQuery 3.0+ here are some other changes you'll have to make:
.unbind() deprecated
Replace all instances of .unbind
with .off
.removeAttribute() is not a function
Change lines 580-581 to use jQuery's .removeAttr()
instead:
Old code:
580: content[0].style.removeAttribute('filter');
581: wrap[0].style.removeAttribute('filter');
New code:
580: content.removeAttr('filter');
581: wrap.removeAttr('filter');
This combined with the other patch mentioned above solved my compatibility issues.
Java : Accessing a class within a package, which is the better way?
No, it doesn't save you memory.
Also note that you don't have to import Math
at all. Everything in java.lang
is imported automatically.
A better example would be something like an ArrayList
import java.util.ArrayList;
....
ArrayList<String> i = new ArrayList<String>();
Note I'm importing the ArrayList
specifically. I could have done
import java.util.*;
But you generally want to avoid large wildcard imports to avoid the problem of collisions between packages.
Specify the date format in XMLGregorianCalendar
Yeah Got it...
Date dob=null;
DateFormat df=new SimpleDateFormat("dd/MM/yyyy");
dob=df.parse( "13/06/1983" );
GregorianCalendar cal = new GregorianCalendar();
cal.setTime(dob);
XMLGregorianCalendar xmlDate = DatatypeFactory.newInstance().newXMLGregorianCalendarDate(cal.get(Calendar.YEAR), cal.get(Calendar.MONTH)+1, cal.get(Calendar.DAY_OF_MONTH), DatatypeConstants.FIELD_UNDEFINED);
This will give it in correct format.
What is "loose coupling?" Please provide examples
When you create an object of a class using new
keyword in some other class, you are actually doing tight coupling (bad practice) instead you should use loose coupling which is a good practice
---A.java---
package interface_package.loose_coupling;
public class A {
void display(InterfaceClass obji)
{
obji.display();
System.out.println(obji.getVar());
}
}
---B.java---
package interface_package.loose_coupling;
public class B implements InterfaceClass{
private String var="variable Interface";
public String getVar() {
return var;
}
public void setVar(String var) {
this.var = var;
}
@Override
public void display() {
// TODO Auto-generated method stub
System.out.println("Display Method Called");
}
}
---InterfaceClass---
package interface_package.loose_coupling;
public interface InterfaceClass {
void display();
String getVar();
}
---MainClass---
package interface_package.loose_coupling;
public class MainClass {
public static void main(String[] args) {
// TODO Auto-generated method stub
A obja=new A();
B objb=new B();
obja.display(objb); //Calling display of A class with object of B class
}
}
Explanation:
In above example, we have two classes A and B
Class B implements Interface i.e. InterfaceClass.
InterfaceClass defines a Contract for B class as InterfaceClass have abstract methods of B class that can be access by any other class for example A.
In Class A we have display method which can except object of class which implements InterfaceClass (in our case it is B class). And on that object method of class A is calling display() and getVar() of class B
In MainClass we have created object of Class A and B. And calling display method of A by passing object of B class i.e. objb. Display method of A will be called with object of B class.
Now talking about loose coupling. Suppose in future you have to change the name of Class B to ABC then you do not have to change its name in display method of class B, just make the object of new (ABC class) and pass it to the display method in MailClass. You do not have to change anything in Class A
ref: http://p3lang.com/2013/06/loose-coupling-example-using-interface/
Problems with installation of Google App Engine SDK for php in OS X
It's likely that the download was corrupted if you are getting an error with the disk image. Go back to the downloads page at https://developers.google.com/appengine/downloads and look at the SHA1 checksum. Then, go to your Terminal app on your mac and run the following:
openssl sha1 [put the full path to the file here without brackets]
For example:
openssl sha1 /Users/me/Desktop/myFile.dmg
If you get a different value than the one on the Downloads page, you know your file is not properly downloaded and you should try again.
Error: Could not create the Java Virtual Machine Mac OSX Mavericks
There can be one more reason for such behavior - you delete current working directory.
For example:
# in terminal #1
cd /home/user/myJavaApp
# in terminal #2
rm -rf /home/user/myJavaApp
# in terminal #1
java -jar myJar.jar
Error: Could not create the Java Virtual Machine.
Error: A fatal exception has occurred. Program will exit.
How can I simulate a click to an anchor tag?
Quoted from https://developer.mozilla.org/en/DOM/element.click
The click method is intended to be used with INPUT elements of type button, checkbox, radio, reset or submit. Gecko does not implement the click method on other elements that might be expected to respond to mouse–clicks such as links (A elements), nor will it necessarily fire the click event of other elements.
Non–Gecko DOMs may behave differently.
Unfortunately it sounds like you have already discovered the best solution to your problem.
As a side note, I agree that your solution seems less than ideal, but if you encapsulate the functionality inside a method (much like JQuery would do) it is not so bad.
How do I POST JSON data with cURL?
You could also put your JSON content in a file and pass it to curl using the --upload-file
option via standard input, like this:
echo 'my.awesome.json.function({"do" : "whatever"})' | curl -X POST "http://url" -T -
Vector of structs initialization
If you want to use the new current standard, you can do so:
sub.emplace_back ("Math", 70, 0);
or
sub.push_back ({"Math", 70, 0});
These don't require default construction of subject
.
How to make HTTP Post request with JSON body in Swift
var request = URLRequest(url: URL(string: "your URL")!)
request.httpMethod = "POST"
let postString = String(format: "email=%@&lang=%@", arguments: [txt_emailVirify.text!, language!])
print(postString)
emailString = txt_emailVirify.text!
request.httpBody = postString.data(using: .utf8)
request.addValue("delta141forceSEAL8PARA9MARCOSBRAHMOS", forHTTPHeaderField: "Authorization")
request.addValue("application/x-www-form-urlencoded", forHTTPHeaderField: "Content-Type")
request.addValue("application/json", forHTTPHeaderField: "Accept")
let task = URLSession.shared.dataTask(with: request) { data, response, error in
guard let data = data, error == nil
else
{
print("error=\(String(describing: error))")
return
}
do
{
let dictionary = try JSONSerialization.jsonObject(with: data, options: .allowFragments) as! NSDictionary
print(dictionary)
let status = dictionary.value(forKey: "status") as! String
let sts = Int(status)
DispatchQueue.main.async()
{
if sts == 200
{
print(dictionary)
}
else
{
self.alertMessageOk(title: self.Alert!, message: dictionary.value(forKey: "message") as! String)
}
}
}
catch
{
print(error)
}
}
task.resume()
json call with C#
Its just a sample of how to post Json data and get Json data to/from a Rest API in BIDS 2008 using System.Net.WebRequest and without using newtonsoft. This is just a sample code and definitely can be fine tuned (well tested and it works and serves my test purpose like a charm). Its just to give you an Idea. I wanted this thread but couldn't find hence posting this.These were my major sources from where I pulled this.
Link 1 and Link 2
Code that works(unit tested)
//Get Example
var httpWebRequest = (System.Net.HttpWebRequest)System.Net.WebRequest.Create("https://abc.def.org/testAPI/api/TestFile");
httpWebRequest.ContentType = "application/json";
httpWebRequest.Method = "GET";
var username = "usernameForYourApi";
var password = "passwordForYourApi";
var bytes = Encoding.UTF8.GetBytes(username + ":" + password);
httpWebRequest.Headers.Add("Authorization", "Basic " + Convert.ToBase64String(bytes));
var httpResponse = (System.Net.HttpWebResponse)httpWebRequest.GetResponse();
using (StreamReader streamReader = new StreamReader(httpResponse.GetResponseStream()))
{
string result = streamReader.ReadToEnd();
Dts.Events.FireInformation(3, "result from readng stream", result, "", 0, ref fireagain);
}
//Post Example
var httpWebRequestPost = (System.Net.HttpWebRequest)System.Net.WebRequest.Create("https://abc.def.org/testAPI/api/TestFile");
httpWebRequestPost.ContentType = "application/json";
httpWebRequestPost.Method = "POST";
bytes = Encoding.UTF8.GetBytes(username + ":" + password);
httpWebRequestPost.Headers.Add("Authorization", "Basic " + Convert.ToBase64String(bytes));
//POST DATA newtonsoft didnt worked with BIDS 2008 in this test package
//json https://stackoverflow.com/questions/6201529/how-do-i-turn-a-c-sharp-object-into-a-json-string-in-net
// fill File model with some test data
CSharpComplexClass fileModel = new CSharpComplexClass();
fileModel.CarrierID = 2;
fileModel.InvoiceFileDate = DateTime.Now;
fileModel.EntryMethodID = EntryMethod.Manual;
fileModel.InvoiceFileStatusID = FileStatus.NeedsReview;
fileModel.CreateUserID = "37f18f01-da45-4d7c-a586-97a0277440ef";
string json = new JavaScriptSerializer().Serialize(fileModel);
Dts.Events.FireInformation(3, "reached json", json, "", 0, ref fireagain);
byte[] byteArray = Encoding.UTF8.GetBytes(json);
httpWebRequestPost.ContentLength = byteArray.Length;
// Get the request stream.
Stream dataStream = httpWebRequestPost.GetRequestStream();
// Write the data to the request stream.
dataStream.Write(byteArray, 0, byteArray.Length);
// Close the Stream object.
dataStream.Close();
// Get the response.
WebResponse response = httpWebRequestPost.GetResponse();
// Display the status.
//Console.WriteLine(((HttpWebResponse)response).StatusDescription);
Dts.Events.FireInformation(3, "Display the status", ((HttpWebResponse)response).StatusDescription, "", 0, ref fireagain);
// Get the stream containing content returned by the server.
dataStream = response.GetResponseStream();
// Open the stream using a StreamReader for easy access.
StreamReader reader = new StreamReader(dataStream);
// Read the content.
string responseFromServer = reader.ReadToEnd();
Dts.Events.FireInformation(3, "responseFromServer ", responseFromServer, "", 0, ref fireagain);
References in my test script task inside BIDS 2008(having SP1 and 3.5 framework)
Javascript array value is undefined ... how do I test for that
You are checking it the array index contains a string "undefined"
, you should either use the typeof
operator:
typeof predQuery[preId] == 'undefined'
Or use the undefined
global property:
predQuery[preId] === undefined
The first way is safer, because the undefined
global property is writable, and it can be changed to any other value.
Using .Select and .Where in a single LINQ statement
Did you add the Select()
after the Where()
or before?
You should add it after, because of the concurrency logic:
1 Take the entire table
2 Filter it accordingly
3 Select only the ID's
4 Make them distinct.
If you do a Select first, the Where clause can only contain the ID attribute because all other attributes have already been edited out.
Update: For clarity, this order of operators should work:
db.Items.Where(x=> x.userid == user_ID).Select(x=>x.Id).Distinct();
Probably want to add a .toList()
at the end but that's optional :)
Create list of object from another using Java 8 Streams
An addition to the solution by @Rafael Teles. The syntactic sugar Collectors.mapping
does the same in one step:
//...
List<Employee> employees = persons.stream()
.filter(p -> p.getLastName().equals("l1"))
.collect(
Collectors.mapping(
p -> new Employee(p.getName(), p.getLastName(), 1000),
Collectors.toList()));
Detailed example can be found here
Is it possible to overwrite a function in PHP
Monkey patch in namespace php >= 5.3
A less evasive method than modifying the interpreter is the monkey patch.
Monkey patching is the art of replacing the actual implementation with a similar "patch" of your own.
Ninja skills
Before you can monkey patch like a PHP Ninja we first have to understand PHPs namespaces.
Since PHP 5.3 we got introduced to namespaces which you might at first glance denote to be equivalent to something like java packages perhaps, but it's not quite the same. Namespaces, in PHP, is a way to encapsulate scope by creating a hierarchy of focus, especially for functions and constants. As this topic, fallback to global functions, aims to explain.
If you don't provide a namespace when calling a function, PHP first looks in the current namespace then moves down the hierarchy until it finds the first function declared within that prefixed namespace and executes that. For our example if you are calling print_r();
from namespace My\Awesome\Namespace;
What PHP does is to first look for a function called My\Awesome\Namespace\print_r();
then My\Awesome\print_r();
then My\print_r();
until it finds the PHP built in function in the global namespace \print_r();
.
You will not be able to define a function print_r($object) {}
in the global namespace because this will cause a name collision since a function with that name already exists.
Expect a fatal error to the likes of:
Fatal error: Cannot redeclare print_r()
But nothing stops you, however, from doing just that within the scope of a namespace.
Patching the monkey
Say you have a script using several print_r();
calls.
Example:
<?php
print_r($some_object);
// do some stuff
print_r($another_object);
// do some other stuff
print_r($data_object);
// do more stuff
print_r($debug_object);
But you later change your mind and you want the output wrapped in <pre></pre>
tags instead. Ever happened to you?
Before you go and change every call to print_r();
consider monkey patching instead.
Example:
<?php
namespace MyNamespace {
function print_r($object)
{
echo "<pre>", \print_r($object, true), "</pre>";
}
print_r($some_object);
// do some stuff
print_r($another_object);
// do some other stuff
print_r($data_object);
// do more stuff
print_r($debug_object);
}
Your script will now be using MyNamespace\print_r();
instead of the global \print_r();
Works great for mocking unit tests.
nJoy!
How do I embed PHP code in JavaScript?
Here is an example:
html_code +="<td>" +
"<select name='[row"+count+"]' data-placeholder='Choose One...' class='chosen-select form-control' tabindex='2'>"+
"<option selected='selected' disabled='disabled' value=''>Select Exam Name</option>"+
"<?php foreach($NM_EXAM as $ky=>$row) {
echo '<option value='."$row->EXAM_ID". '>' . $row->EXAM_NAME . '</option>';
} ?>"+
"</select>"+
"</td>";
Or
echo '<option value=\"'.$row->EXAM_ID. '\">' . $row->EXAM_NAME . '</option>';
How to align checkboxes and their labels consistently cross-browsers
I have not completely tested my solution, but it seems to work great.
My HTML is simply:
<label class="checkbox"><input type="checkbox" value="0000">0000 - 0100</label>
I then set all checkboxes to 24px
for both height and width. To make the text aligned I make the label's line-height
also 24px
and assign vertical-align: top;
like so:
EDIT: After IE testing I added vertical-align: bottom;
to the input and changed the label's CSS. You may find you need a conditional IE css case to sort out padding - but the text and box are inline.
_x000D_
_x000D_
input[type="checkbox"] {_x000D_
width: 24px;_x000D_
height: 24px;_x000D_
vertical-align: bottom;_x000D_
}_x000D_
label.checkbox {_x000D_
vertical-align: top;_x000D_
line-height: 24px;_x000D_
margin: 2px 0;_x000D_
display: block;_x000D_
height: 24px;_x000D_
}
_x000D_
<label class="checkbox"><input type="checkbox" value="0000">0000 - 0100</label>_x000D_
<label class="checkbox"><input type="checkbox" value="0100">0100 - 0200</label>_x000D_
<label class="checkbox"><input type="checkbox" value="0200">0200 - 0300</label>_x000D_
<label class="checkbox"><input type="checkbox" value="0300">0300 - 0400</label>
_x000D_
_x000D_
_x000D_
If anyone finds that this doesn't work, please kindly let me know. Here is it in action (in Chrome and IE - apologies as screenshots were taken on retina and using parallels for IE):
PHP - Check if two arrays are equal
$arraysAreEqual = ($a == $b); // TRUE if $a and $b have the same key/value pairs.
$arraysAreEqual = ($a === $b); // TRUE if $a and $b have the same key/value pairs in the same order and of the same types.
See Array Operators.
EDIT
The inequality operator is !=
while the non-identity operator is !==
to match the equality
operator ==
and the identity operator ===
.
Move div to new line
What about something like this.
<div id="movie_item">
<div class="movie_item_poster">
<img src="..." style="max-width: 100%; max-height: 100%;">
</div>
<div id="movie_item_content">
<div class="movie_item_content_year">year</div>
<div class="movie_item_content_title">title</div>
<div class="movie_item_content_plot">plot</div>
</div>
<div class="movie_item_toolbar">
Lorem Ipsum...
</div>
</div>
You don't have to float both movie_item_poster
AND movie_item_content
. Just float one of them...
#movie_item {
position: relative;
margin-top: 10px;
height: 175px;
}
.movie_item_poster {
float: left;
height: 150px;
width: 100px;
}
.movie_item_content {
position: relative;
}
.movie_item_content_title {
}
.movie_item_content_year {
float: right;
}
.movie_item_content_plot {
}
.movie_item_toolbar {
clear: both;
vertical-align: bottom;
width: 100%;
height: 25px;
}
Here it is as a JSFiddle.
How to create a GUID in Excel?
for me it is correct, in Excel spanish
=CONCATENAR(
DEC.A.HEX(ALEATORIO.ENTRE(0,4294967295),8),"-",
DEC.A.HEX(ALEATORIO.ENTRE(0,65535),4),"-",
DEC.A.HEX(ALEATORIO.ENTRE(16384,20479),4),"-",
DEC.A.HEX(ALEATORIO.ENTRE(32768,49151),4),"-",
DEC.A.HEX(ALEATORIO.ENTRE(0,65535),4),
DEC.A.HEX(ALEATORIO.ENTRE(0,4294967295),8)
)
What's an Aggregate Root?
Aggregate means collection of something.
root is like top node of tree, from where we can access everything like <html>
node in web page document.
Blog Analogy, A user can have many posts and each post can have many comments. so if we fetch any user then it can act as root to access all the related posts and further comments of those posts. These are all together said to be collection or Aggregated
Convert array to JSON string in swift
As it stands you're converting it to data, then attempting to convert the data to to an object as JSON (which fails, it's not JSON) and converting that to a string, basically you have a bunch of meaningless transformations.
As long as the array contains only JSON encodable values (string, number, dictionary, array, nil) you can just use NSJSONSerialization to do it.
Instead just do the array->data->string parts:
Swift 3/4
let array = [ "one", "two" ]
func json(from object:Any) -> String? {
guard let data = try? JSONSerialization.data(withJSONObject: object, options: []) else {
return nil
}
return String(data: data, encoding: String.Encoding.utf8)
}
print("\(json(from:array as Any))")
Original Answer
let array = [ "one", "two" ]
let data = NSJSONSerialization.dataWithJSONObject(array, options: nil, error: nil)
let string = NSString(data: data!, encoding: NSUTF8StringEncoding)
although you should probably not use forced unwrapping, it gives you the right starting point.
How to copy text from a div to clipboard
Made a modification to the solutions, so it will work with multiple divs based on class instead of specific IDs. For example, if you have multiple blocks of code. This assumes that the div class is set to "code".
<script>
$( document ).ready(function() {
$(".code").click(function(event){
var range = document.createRange();
range.selectNode(this);
window.getSelection().removeAllRanges(); // clear current selection
window.getSelection().addRange(range); // to select text
document.execCommand("copy");
window.getSelection().removeAllRanges();// to deselect
});
});
</script>
Sum values from multiple rows using vlookup or index/match functions
You should use Ctrl+shift+enter when using the =SUM(VLOOKUP(A9,A1:D5,{2,3,4,},FALSE))
that results in {=SUM(VLOOKUP(A9,A1:D5,{2,3,4,},FALSE))} en also works.