How to execute Python scripts in Windows

Question

I have a simple script blah py  using Python 2    import sys print sys argv 1    If I execute my script by   python c       blah py argument   It prints argument but if I execute script by   blah py argument   error occurs      IndexError      So arguments do not pass to script   python exe in PATH  Folder with blah py also in PATH  python exe is default program to execute   py files   What is the problem

User · Accepted Answer

When you execute a script without typing "python" in front, you need to know two things about how Windows invokes the program. First is to find out what kind of file Windows thinks it is:

    C:\>assoc .py
    .py=Python.File

Next, you need to know how Windows is executing things with that extension. It's associated with the file type "Python.File", so this command shows what it will be doing:

    C:\>ftype Python.File
    Python.File="c:\python26\python.exe" "%1" %*

So on my machine, when I type "blah.py foo", it will execute this exact command, with no difference in results than if I had typed the full thing myself:

    "c:\python26\python.exe" "blah.py" foo

If you type the same thing, including the quotation marks, then you'll get results identical to when you just type "blah.py foo". Now you're in a position to figure out the rest of your problem for yourself.

(Or post more helpful information in your question, like actual cut-and-paste copies of what you see in the console. Note that people who do that type of thing get their questions voted up, and they get reputation points, and more people are likely to help them with good answers.)

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Even if assoc and ftype display the correct information, it may happen that the arguments are stripped off. What may help in that case is directly fixing the relevant registry keys for Python. Set the

HKEY_CLASSES_ROOT\Applications\python26.exe\shell\open\command

key to:

"C:\Python26\python26.exe" "%1" %*

Likely, previously, %* was missing. Similarly, set

 HKEY_CLASSES_ROOT\py_auto_file\shell\open\command

to the same value. See http://eli.thegreenplace.net/2010/12/14/problem-passing-arguments-to-python-scripts-on-windows/

HKEY_CLASSES_ROOT\Applications\python.exe\shell\open\command The registry path may vary, use python26.exe or python.exe or whichever is already in the registry.

HKEY_CLASSES_ROOT\py_auto_file\shell\open\command

User · Answer

I encountered the same problem but in the context of needing to package my code for Windows users  coming from Linux   My package contains a number of scripts with command line options   I need these scripts to get installed in the appropriate location on Windows users  machines so that they can invoke them from the command line  As the package is supposedly user-friendly  asking my users to change their registry to run these scripts would be impossible   I came across a solution that the folks at Continuum use for Python scripts that come with their Anaconda package -- check out your Anaconda Scripts directory for examples   For a Python script test  create two files  a test bat and a test-script py   test bat looks as follows  the  bat files in Anaconda Scripts call python exe with a relative path which I adapted for my purposes     echo off set PYFILE   f0 set PYFILE  PYFILE  0 -4 -script py  python exe    PYFILE        test-script py is your actual Python script   import sys print sys argv   If you leave these two files in your local directory you can invoke your Python script through the  bat file by doing  test bat hello world   C        test-scripy py    hello    world     If you copy both files to a location that is on your PATH  such as Anaconda Scripts  then you can even invoke your script by leaving out the  bat suffix  test hello world   C      Anaconda  Scripts  test-scripy py    hello    world     Disclaimer  I have no idea what s going on and how this works and so would appreciate any explanation

User · Answer

If that s what I understood  it s like this   C  Users  username  AppData Local Programs Python Python version    COPY  not delete  python exe and rename to py exe and execute   py filename py

User · Answer

Simply run the command   C  gt python   file name py   Assuming the file name is within same folder and Python has already been added to environment variables

User · Answer

Found an incredibly useful answer here  How to run different python versions in cmd   I would suggest using the Python Launcher for Windows utility that introduced was into Python 3 3 a while ago  You can also manually download and install it directly from the author s website for use with earlier versions of Python 2 and 3  Regardless of how you obtain it  after installation it will have associated itself with all the standard Python file extensions  i e   py   pyw   pyc  and  pyo files   You ll not only be able to explicitly control which version is used at the command-prompt  but also on a script-by-script basis by adding Linux Unix-y shebang    usr bin env pythonX comments at the beginning of your Python scripts   As J F  Sebastian suggests  Python Launcher for Windows is the best and default choice for launching different version of Python in Windows  It used to be a third-party tool  but now it is officially supported since Python 3 3   New in version 3 3  The Python launcher for Windows is a utility which aids in the location and execution of different Python versions  It allows scripts  or the command-line  to indicate a preference for a specific Python version  and will locate and execute that version   This is a great tool just use it

User · Answer

Additionally  if you want to be able to run your python scripts without typing the  py  or  pyw  on the end of the file name  you need to add  PY  or  PY  PYW  to the list of extensions in the PATHEXT environment variable   In Windows 7   right-click on Computer left-click Properties left-click Advanced system settings left-click the Advanced tab left-click Environment Variables    under  system variables  scroll down until you see PATHEXT left-click on PATHEXT to highlight it left-click Edit    Edit  Variable value  so that it contains   PY   the End key will skip to the end  left-click OK left-click OK left-click OK  Note  1  command-prompt windows won t see the change w o being closed and reopened   Note  2  the difference between the  py and  pyw extensions is that the former opens a command prompt when run  and the latter doesn t   On my computer  I added   PY  PYW as the last  lowest-priority  extensions  so the  before  and  after  values of PATHEXT were   before   COM  EXE  BAT  CMD  VBS  VBE  JS  JSE  WSF  WSH  MSC  after  COM  EXE  BAT  CMD  VBS  VBE  JS  JSE  WSF  WSH  MSC  PY  PYW  Here are some instructive commands   C   gt echo  pathext   COM  EXE  BAT  CMD  VBS  VBE  JS  JSE  WSF  WSH  MSC  PY  PYW  C   gt assoc  py  py Python File  C   gt ftype Python File Python File  C  Python32 python exe    1      C   gt assoc  pyw  pyw Python NoConFile  C   gt ftype Python NoConFile Python NoConFile  C  Python32 pythonw exe    1      C   gt type c  windows helloworld py print  Hello  world       always use a comma for direct address  C   gt helloworld Hello  world   C   gt

User · Answer

On Windows    To run a python module without typing  python    --  Right click any python   py  file  --  Set the open with property to  python exe    --  Check the  always use this program for this file type   --  Append the path of python exe to variable environment e g  append  C  Python27 to PATH environment variable   To Run a python module without typing   py  extension  --  Edit PATHEXT system variable and append   PY  extension to the list

User · Answer

How to execute Python scripts in Windows    You could install pylauncher  It is used to launch  py   pyw   pyc   pyo files and supports multiple Python installations   T   gt  blah py argument   You can run your Python script without specifying  py extension if you have  py   pyw in PATHEXT environment variable   T   gt  blah argument   It adds support for shebang     header line  to select desired Python version on Windows if you have multiple versions installed  You could use  nix-compatible syntax     usr bin env python   You can specify version explicitly e g   to run using the latest installed Python 3 version   T   gt  py -3 blah py argument   It should also fix your sys argv issue as a side-effect

User · Answer

you should make the default application to handle python files be python exe   right click a   py file  select  Open With  dialog   In there select  python exe  and check  always use this program for this file type   something like that    then your python files will always be run using python exe

User · Answer

Can you execute python exe from any map  If you do not  chek if you have proper values for python exe in PATH enviroment  Are you in same directory than blah py  Check this by issuing command -  edit blah py and check if you can open this file  EDIT   In that case you can not   python arg means that you call python exe whit some parameters which python assume that is filename of script you want to run   You can create bat file whit lines in your path map and run  bat file  Example  In one of Path maps create blah py bat Edit file and put line  python C  Somedir blah py   You can now run blah py from anywere  becuase you do not need to put  bat extention when running bat files

[python] How to execute Python scripts in Windows?

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