How can I read inputs as numbers

Question

Why are x and y strings instead of ints in the below code    Note  in Python 2 x use raw input    In Python 3 x use input    raw input   was renamed to input   in Python 3 x   play   True  while play       x   input  Enter a number         y   input  Enter a number          print x   y      print x - y      print x   y      print x   y      print x   y       if input  Play again         no           play   False

User · Answer

n int input    for i in range n       n input       n int n      arr1 list map int input   split       the for loop shall run  n  number of times   the second  n  is the length of the array  the last statement maps the integers to a list and takes input in space separated form   you can also return the array at the end of for loop

User · Answer

While in your example  int input       does the trick in any case  python-future s builtins input is worth consideration since that makes sure your code works for both Python 2 and 3 and disables Python2 s default behaviour of input trying to be  clever  about the input data type  builtins input basically just behaves like raw input

User · Answer

I encountered a problem of taking integer input while solving a problem on CodeChef  where two integers - separated by space - should be read from one line   While int input    is sufficient for a single integer  I did not find a direct way to input two integers   I tried this   num   input   num1   0 num2   0  for i in range len num        if num i                  break  num1   int num  i   num2   int num i 1      Now I use num1 and  num2 as integers   Hope this helps

User · Answer

For multiple integer in a single line  map might be better   arr   map int  raw input   split      If the number is already known   like 2 integers   you can use  num1  num2   map int  raw input   split

User · Answer

def dbz        try          r   raw input  Enter number            if r isdigit                i   int raw input  Enter divident                 d   int r  i             print  O p is -   d         else              print  Not a number      except Exception  e          print  Program halted incorrect data entered  type e  dbz    Or   num   input  Enter Number     input  will accept only numbers

User · Answer

In Python 3 x  raw input was renamed to input and the Python 2 x input was removed     This means that  just like raw input  input in Python 3 x always returns a string object   To fix the problem  you need to explicitly make those inputs into integers by putting them in int   x   int input  Enter a number      y   int input  Enter a number

User · Answer

Convert to integers   my number   int input  enter the number      Similarly for floating point numbers   my decimalnumber   float input  enter the number

User · Answer

input    Python 3  and raw input    Python 2  always return strings  Convert the result to integer explicitly with int     x   int input  Enter a number      y   int input  Enter a number

User · Answer

Solution Since Python 3  input returns a string which you have to explicitly convert to ints  with int  like this x   int input  quot Enter a number   quot    y   int input  quot Enter a number   quot     You can accept numbers of any base and convert them directly to base-10 with the int function  like this  gt  gt  gt  data   int input  quot Enter a number   quot    8  Enter a number  777  gt  gt  gt  data 511  gt  gt  gt  data   int input  quot Enter a number   quot    16  Enter a number  FFFF  gt  gt  gt  data 65535  gt  gt  gt  data   int input  quot Enter a number   quot    2  Enter a number  10101010101  gt  gt  gt  data 1365  The second parameter tells what is the base of the numbers entered and then internally it understands and converts it  If the entered data is wrong it will throw a ValueError   gt  gt  gt  data   int input  quot Enter a number   quot    2  Enter a number  1234 Traceback  most recent call last     File  quot  lt input gt  quot   line 1  in  lt module gt  ValueError  invalid literal for int   with base 2   1234   For values that can have a fractional component  the type would be float rather than int  x   float input  quot Enter a number  quot     Differences between Python 2 and 3 Summary  Python 2 s input function evaluated the received data  converting it to an integer implicitly  read the next section to understand the implication   but Python 3 s input function does not do that anymore  Python 2 s equivalent of Python 3 s input is the raw input function   Python 2 x There were two functions to get user input  called input and raw input  The difference between them is  raw input doesn t evaluate the data and returns as it is  in string form  But  input will evaluate whatever you entered and the result of evaluation will be returned  For example   gt  gt  gt  import sys  gt  gt  gt  sys version  2 7 6  default  Mar 22 2014  22 59 56   n GCC 4 8 2    gt  gt  gt  data   input  quot Enter a number   quot   Enter a number  5   17  gt  gt  gt  data  type data   22   lt type  int  gt    The data 5   17 is evaluated and the result is 22  When it evaluates the expression 5   17  it detects that you are adding two numbers and so the result will also be of the same int type  So  the type conversion is done for free and 22 is returned as the result of input and stored in data variable  You can think of input as the raw input composed with an eval call   gt  gt  gt  data   eval raw input  quot Enter a number   quot    Enter a number  5   17  gt  gt  gt  data  type data   22   lt type  int  gt    Note  you should be careful when you are using input in Python 2 x  I explained why one should be careful when using it  in this answer  But  raw input doesn t evaluate the input and returns as it is  as a string   gt  gt  gt  import sys  gt  gt  gt  sys version  2 7 6  default  Mar 22 2014  22 59 56   n GCC 4 8 2    gt  gt  gt  data   raw input  quot Enter a number   quot   Enter a number  5   17  gt  gt  gt  data  type data    5   17    lt type  str  gt    Python 3 x Python 3 x s input and Python 2 x s raw input are similar and raw input is not available in Python 3 x   gt  gt  gt  import sys  gt  gt  gt  sys version  3 4 0  default  Apr 11 2014  13 05 11   n GCC 4 8 2    gt  gt  gt  data   input  quot Enter a number   quot   Enter a number  5   17  gt  gt  gt  data  type data    5   17    lt class  str  gt

User · Answer

Multiple questions require input for several integers on single line   The best way is to input the whole string of numbers one one line and then split them to integers  Here is a Python 3 version   a      p   input   p   p split         for i in p      a append int i     Also a list comprehension can be used  p   input   split  whatever the seperator is     And to convert all the inputs from string to int we do the following  x    int i  for i in p  print x  end        shall print the list elements in a straight line

[python] How can I read inputs as numbers?

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