Python – os.popen Does Not Work with Parameters Inside Quotes When Command is in Quotes

To be honest, all I really know is that this python code returns ” for me,

[Dbg]>>> print command
"C:\automated tasks\GoldMine_Replace\GoldMine_Replace.exe" -lg -pfd5 -r"3XDYQ2#PK [Dbg]>>> os.popen(command).read()
''

while running the same command at the DOS prompt returns good stuff.
C:\>"C:\automated tasks\GoldMine_Replace\GoldMine_Replace.exe" -lg -pfd5 -r"3XDYQ2#PK Success

Additionally this Python bug seems to imply that os.system and the os.popen's just don't work quite right on Windows.

But don't get frusterated. Just do a cheap workaround and move/rename your executable (put it in a batch file if you have to) so that you don't need to put the command in quotes. That means making it have no spaces in it's filepath. That's what worked for me. I just moved the executable GoldMine_Replace.exe to the C:\ directory.

There's also a bit of discussion here but no real insight (just people claiming this problem doesn't exist?)

Posted by Greg Pinero (Primary Searcher) on Oct 4th, 2006 and is filed under win32.

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4 Responses to “Python – os.popen Does Not Work with Parameters Inside Quotes When Command is in Quotes”

  1. Fredrik says:
    October 4th, 2006 at 5:34 pm

    That’s a well-known bug in *Windows* command-line parser. The work-around is also well-known: just add an *extra* quote at the beginning of the line:

    “”\program files\big corporation\program.exe” “arg”

  2. Greg Pinero (Primary Searcher) says:
    October 4th, 2006 at 5:44 pm

    Fredrik, for some reason the extra quote didn’t work for me in this case. I’m not sure why. Nonetheless the extra quote is the best work-around to try first.

  3. Fuzzyman says:
    October 5th, 2006 at 2:26 pm

    I *thought* that the solution to this bug was to add extra quotes as follows :

    “”\program files\big corporation\program.exe” “arg”"

    One extra at the start and one at the end.

    An alternative is to use the win32api call win32api.GetShortName (I think that is correct – something like that anyway) so that the filename doesn’t need quoting.

  4. Greg Pinero (Primary Searcher) says:
    October 5th, 2006 at 2:47 pm

    Good ideas, Fuzzyman. Those are certainly worth trying. BTW, the “big corporation” in the file path amuses me for some reason ;-)