Windows is not passing command line arguments to Python programs executed from the shell
PythonWindowsRegistryCommand Line-ArgumentsFile AssociationPython Problem Overview
I'm having trouble getting command line arguments passed to Python programs if I try to execute them directly as executable commands from a Windows command shell. For example, if I have this program (test.py):
import sys
print "Args: %r" % sys.argv[1:]
And execute:
>test foo
Args: []
as compared to:
>python test.py foo
Args: ['foo']
My configuration has:
PATH=...;C:\python25;...
PATHEXT=...;.PY;....
>assoc .py
.py=Python.File
>ftype | grep Python
Python.CompiledFile="C:\Python25\python.exe" "%1" %*
Python.File="C:\Python25\python.exe" "%1" %*
Python.NoConFile="C:\Python25\pythonw.exe" "%1" %*
Python Solutions
Solution 1 - Python
I think I solved this. For some reason there is a SECOND place in the registry (besides that shown by the file associations stored in HKEY_CLASSES_ROOT\Python.File\shell\open\command):
[HKEY_CLASSES_ROOT\Applications\python.exe\shell\open\command]
@="\"C:\\Python25\\python.exe\" \"%1\" %*"
This seems to be the controlling setting on my system. The registry setting above adds the "%*" to pass all arguments to python.exe (it was missing in my registry for some reason).
Solution 2 - Python
My setting was under yet another registry key, HKEY_CLASSES_ROOT\py_auto_file. The other keys mentioned also existed, but Windows was using this one for some reason.
Solution 3 - Python
For Python 3.3 on Windows 7, my setting was under another registry key; the key I changed to make the arguments get passed was
HKEY_USERS\S-1-5-21-3922133726-554333396-2662258059-1000_Classes\py_auto_file\shell\open\command
It was "C:\Python\Python33\python.exe" "%1". I only appended %* to it. The key's value is now "C:\Python\Python33\python.exe" "%1" %*.
I had several (at least five) other keys with the value "C:\Python\Python33\python.exe" "%1", but this is the one I changed that made it work.
Solution 4 - Python
Here are .reg files to fix for Python 3.6, 2.7 and Anaconda3:
python-3.6.0.reg
Windows Registry Editor Version 5.00
[HKEY_CLASSES_ROOT\.py]
@="Python.File"
"Content Type"="text/plain"
[HKEY_CLASSES_ROOT\.pyc]
@="Python.CompiledFile"
"Content Type"="text/plain"
[HKEY_CLASSES_ROOT\.pyw]
@="Python.NoConFile"
"Content Type"="text/plain"
[HKEY_CLASSES_ROOT\py_auto_file]
[HKEY_CLASSES_ROOT\py_auto_file\DefaultIcon]
@="C:\\Python36\\DLLs\\py.ico"
[HKEY_CLASSES_ROOT\py_auto_file\shell\open\command]
@="\"C:\\Python36\\python.exe\" \"%1\" %*"
[HKEY_CLASSES_ROOT\Python.File]
@="Python File"
[HKEY_CLASSES_ROOT\Python.File\DefaultIcon]
@="C:\\Python36\\DLLs\\py.ico"
[HKEY_CLASSES_ROOT\Python.File\shell\open\command]
@="\"C:\\Python36\\python.exe\" \"%1\" %*"
[HKEY_CLASSES_ROOT\Python.CompiledFile]
@="Compiled Python File"
[HKEY_CLASSES_ROOT\Python.CompiledFile\DefaultIcon]
@="C:\\Python36\\DLLs\\pyc.ico"
[HKEY_CLASSES_ROOT\Python.CompiledFile\shell\open\command]
@="\"C:\\Python36\\python.exe\" \"%1\" %*"
[HKEY_CLASSES_ROOT\Python.NoConFile]
@="Python File (no console)"
[HKEY_CLASSES_ROOT\Python.NoConFile\DefaultIcon]
@="C:\\Python36\\DLLs\\py.ico"
[HKEY_CLASSES_ROOT\Python.NoConFile\shell\open\command]
@="\"C:\\Python36\\python.exe\" \"%1\" %*"
python-2.7.0.reg
Windows Registry Editor Version 5.00
[HKEY_CLASSES_ROOT\.py]
@="Python.File"
"Content Type"="text/plain"
[HKEY_CLASSES_ROOT\.pyc]
@="Python.CompiledFile"
"Content Type"="text/plain"
[HKEY_CLASSES_ROOT\.pyw]
@="Python.NoConFile"
"Content Type"="text/plain"
[HKEY_CLASSES_ROOT\py_auto_file]
[HKEY_CLASSES_ROOT\py_auto_file\DefaultIcon]
@="C:\\Python27\\DLLs\\py.ico"
[HKEY_CLASSES_ROOT\py_auto_file\shell\open\command]
@="\"C:\\Python27\\python.exe\" \"%1\" %*"
[HKEY_CLASSES_ROOT\Python.File]
@="Python File"
[HKEY_CLASSES_ROOT\Python.File\DefaultIcon]
@="C:\\Python27\\DLLs\\py.ico"
[HKEY_CLASSES_ROOT\Python.File\shell\open\command]
@="\"C:\\Python27\\python.exe\" \"%1\" %*"
[HKEY_CLASSES_ROOT\Python.CompiledFile]
@="Compiled Python File"
[HKEY_CLASSES_ROOT\Python.CompiledFile\DefaultIcon]
@="C:\\Python27\\DLLs\\pyc.ico"
[HKEY_CLASSES_ROOT\Python.CompiledFile\shell\open\command]
@="\"C:\\Python27\\python.exe\" \"%1\" %*"
[HKEY_CLASSES_ROOT\Python.NoConFile]
@="Python File (no console)"
[HKEY_CLASSES_ROOT\Python.NoConFile\DefaultIcon]
@="C:\\Python27\\DLLs\\py.ico"
[HKEY_CLASSES_ROOT\Python.NoConFile\shell\open\command]
@="\"C:\\Python27\\python.exe\" \"%1\" %*"
ananconda3.reg (change username)
Windows Registry Editor Version 5.00
[HKEY_CLASSES_ROOT\.py]
@="Python.File"
"Content Type"="text/plain"
[HKEY_CLASSES_ROOT\.pyc]
@="Python.CompiledFile"
"Content Type"="text/plain"
[HKEY_CLASSES_ROOT\.pyw]
@="Python.NoConFile"
"Content Type"="text/plain"
[HKEY_CLASSES_ROOT\py_auto_file]
[HKEY_CLASSES_ROOT\py_auto_file\DefaultIcon]
@="C:\\Users\\username\\Anaconda3\\DLLs\\py.ico"
[HKEY_CLASSES_ROOT\py_auto_file\shell\open\command]
@="\"C:\\Users\\username\\Anaconda3\\python.exe\" \"%1\" %*"
[HKEY_CLASSES_ROOT\Python.File]
@="Python File"
[HKEY_CLASSES_ROOT\Python.File\DefaultIcon]
@="C:\\Users\\username\\Anaconda3\\DLLs\\py.ico"
[HKEY_CLASSES_ROOT\Python.File\shell\open\command]
@="\"C:\\Users\\username\\Anaconda3\\python.exe\" \"%1\" %*"
[HKEY_CLASSES_ROOT\Python.CompiledFile]
@="Compiled Python File"
[HKEY_CLASSES_ROOT\Python.CompiledFile\DefaultIcon]
@="C:\\Users\\username\\Anaconda3\\DLLs\\pyc.ico"
[HKEY_CLASSES_ROOT\Python.CompiledFile\shell\open\command]
@="\"C:\\Users\\username\\Anaconda3\\python.exe\" \"%1\" %*"
[HKEY_CLASSES_ROOT\Python.NoConFile]
@="Python File (no console)"
[HKEY_CLASSES_ROOT\Python.NoConFile\DefaultIcon]
@="C:\\Users\\username\\Anaconda3\\DLLs\\py.ico"
[HKEY_CLASSES_ROOT\Python.NoConFile\shell\open\command]
@="\"C:\\Users\\username\\Anaconda3\\python.exe\" \"%1\" %*"
Solution 5 - Python
To make it working for me, I had to use the registry path:
HKEY_CLASSES_ROOT\py_auto_file\shell\open\command
and added a %*
Solution 6 - Python
If fixed this on my Windows 10 system by editing the following registry keys:
Computer\HKEY_CLASSES_ROOT\py_auto_file\shell\open\command
Computer\HKEY_CLASSES_ROOT\Python.File\Shell\Open\Command
Computer\HKEY_CLASSES_ROOT\Applications\python.exe\shell\open\command
to this value:
"C:\Python27\python.exe" "%1" %*
Solution 7 - Python
A lot of thanks for the most of other answers for helping me to find the solution!
My case was to open .py-files with py.exe (not python.exe directly), this case it noted in a couple of comments, but I decided to post this as a separate answer to emphasize the difference.
So I have my .py-files associated with C:\Windows\py.exe and in C:\Windows\py.ini config I have a couple of shebang definitions
[commands]
<my_venv_py> = C:\Programs\my_venv_py\Scripts\python.exe
<my_venv_py_w> = C:\Programs\my_venv_py\Scripts\pythonw.exe
to use in my scripts like this #!<MY_VENV_PY>.
And on Microsoft Windows 7 [Version 6.1.7601] my python script did NOT received the args like this
script.py 1 2
but this worked fine
py script.py 1 2
File associations were OK
> assoc .py
.py=Python.File
> ftype | grep Python
File STDIN:
Python.CompiledFile="C:\Windows\py.exe" "%1" %*
Python.File=C:\Windows\py.exe "%L" %*
Python.NoConFile="C:\Windows\pyw.exe" "%1" %*
I've tried much of registry changes, but the last helped was the following change (saved to a .reg-file and run). I've found this registry key searching "%1" string with initial value "C:\Windows\py.exe" "%1" and added %* in the end as other answers note:
Windows Registry Editor Version 5.00
[HKEY_CLASSES_ROOT\Applications\py.exe\shell\open\command]
@="\"C:\\Windows\\py.exe\" \"%1\" %*"
For information, before I tried to setup these keys and values and did not helped (at least before the noted above):
Windows Registry Editor Version 5.00
[HKEY_CLASSES_ROOT\.py]
@="Python.File"
[HKEY_CURRENT_USER\Software\Classes\.py]
@="Python.File"
[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\.py]
@="Python.File"
[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts\.py]
@="Python.File"
[HKEY_CLASSES_ROOT\py_auto_file]
@="Python File"
[HKEY_CLASSES_ROOT\py_auto_file\shell\open\command]
@="\"C:\\Windows\\py.exe\" \"%1\" %*"
[HKEY_CLASSES_ROOT\Python.File]
@="Python File"
[HKEY_CLASSES_ROOT\Python.File\Shell\Open\command]
@="\"C:\\Windows\\py.exe\" \"%1\" %*"
Solution 8 - Python
Had to modify this in Windows 10 to get it to work (%* at the end)
Computer\HKEY_USERS\S-1-5-21-2364940108-955964078-1358188674-1001\Software\Classes\Applications\py.exe\shell\open\command
Solution 9 - Python
Interesting. Works here using python 2.6 and Windows XP (5.1.2600):
C:\Documents and Settings\hbrown>python test.py foo
['test.py', 'foo']
C:\Documents and Settings\hbrown>test.py foo
['C:\\Documents and Settings\\hbrown\\test.py', 'foo']
C:\Documents and Settings\hbrown>test foo
['C:\\Documents and Settings\\hbrown\\test.py', 'foo']
C:\Documents and Settings\hbrown>type test.py
import sys
print sys.argv
C:\Documents and Settings\hbrown>echo %PATHEXT%
.COM;.EXE;.BAT;.CMD;.VBS;.VBE;.JS;.JSE;.WSF;.WSH;.PY
C:\Documents and Settings\hbrown>assoc .py
.py=Python.File
Solution 10 - Python
Your program associations for .py files might be messed up. Just re-associate .py files with your python executable.
Right click a .py file > Open with > Choose default program ... > [find C:\PythonXY\python.exe]
Solution 11 - Python
I checked all registry keys with python.exe and py_auto_file and made them point to my current python installation including th %* at the end that passes arguments. They were quite a few:
> * HKEY_CLASSES_ROOT\Applications\python.exe\shell\open\command: > * org: "C:\miniconda3\python.exe" "%1" "%" > * changed: "C:\Python35\python.exe" "%1" "%" > > * HKEY_CLASSES_ROOT\py_auto_file\shell\open\command > * org: "C:\Program Files\Sublime Text 3\sublime_text.exe" "%1" > * changed: "C:\Python35\python.exe" "%1" "%" > > * HKEY_CURRENT_USER\Software\Classes\py_auto_file\shell\open\command > * org: "C:\Python35\python.exe" "%1" "%" > > * HKEY_USERS\S-1-5-21-2621213409-1291422344-4183577876-2165\Software\Classes\py_auto_file\shell\open\command > * org: "C:\Python35\python.exe" "%1" "%" > > * HKEY_USERS\S-1-5-21-2621213409-1291422344-4183577876-2165_Classes\py_auto_file\shell\open\command > > * org: "C:\Python35\python.exe" "%1" "%" > > * HKEY_CLASSES_ROOT\Applications\pythonw.exe\shell\open\command > * org: "C:\Python34\pythonw.exe" "%1" > * changed: "C:\Python35\pythonw.exe" "%1" "%" > > * HKEY_CURRENT_USER\Software\Classes\Applications\python.exe\shell\open\command > * org: "C:\Python35\python.exe" "%1" "%"
But that didn't do the job for me. I had to change my default python application as well.
As one can see I have 3 Python versions installed. It is impossible to see which is which here so I tried all three of them as my default python application. Eventually I was able to get my script arguments with one of these three.
Solution 12 - Python
By looking through the Windows registry, I found all the places where anything like
Python36\pythonw.exe "%1" %* appears.
When I type python app.py args at the command prompt, everything works properly.
When I use just the app name (app.py args) Windows opens app.py in Python, but the app fails when it tries to access argv[1], because len(argv) is 1.
Apparently Windows knows enough to pass a py file to Python, but I can't figure out from looking at registry entries how it constructs the command. It appears to be using "%1" rather than "%1" %*.