os.system to invoke an exe which lies in a dir whose name contains whitespace

问题

simply my code is as follows:

file = 'C:\\Exe\\First Version\\filename.exe'
os.system(file)

when I run this program, windowserror is raised, can't find the file specified. I found out the problem has to with the whitespace between "First Version". So Could I find a way circumventing the problem?

PS: what if the variable 'file' will be passed as arg into another func?

回答1:

Putting quotes around the path will work:

file = 'C:\\Exe\\First Version\\filename.exe'
os.system('"' + file + '"')

but a better solution is to use the subprocess module instead:

import subprocess
file = 'C:\\Exe\\First Version\\filename.exe'
subprocess.call([file])

回答2:

Try enclosing it with double quotes.

file = '"C:\\Exe\\First Version\\filename.exe"'
os.system(file)

回答3:

I used this:

import subprocess, shlex
mycmd='"C:\\Program Files\\7-Zip\\7z" x "D:\\my archive.7z" -o"D:\\extract folder" -aou'
subprocess.run(shlex.split(mycmd))

回答4:

It is true that os.system will launch a binary which has spaces in the path by wrapping that path in quotes. (That should be a pretty obvious solution if you are accustom to using a terminal.) By itself, however, that doesn't resolve the more painful problem with this function... Once you do that, you can then run into troubles adding arguments to your command! (Ahh!)

All current recommendations are to use the subprocess module now instead of this old, frowned upon function. One can also use shlx to convert flat strings into lists for those subprocess functions. I've encountered issues or pains with those methods too, which I won't ramble on about... Also, it's sometimes just easier use os.system when all you want is thin wrapper over the shell, which implicitly displays the output streams on console, works synchronously, etc. I sure wish there was a built-in function to execute a command on the shell like this, with absolutely 0 parsing, wrapping, abstracting...

Since there is no built-in without a "filters", here's my solution patch for os.system. This is lifted from an open source library of mine. This has been tested on Windows, Mac, and Ubuntu Linux. I'm aware it's not 100% foolproof, and it's more involved tan one would hop for, but it's not too bad.

When you call this _system() wrapper (passing a string to execute), just surround your long path in quotes and include any arguments that need with and without quotes as well. On the first "token" in the command, this will remove the quotes and escape spaces in the path on Mac or Linux. On Windows, it uses the "short name" by actually resolving what that is on the given environment. That part of the code is a bit tricky. Basically it uses a batch mechanism for the name resolution, and it sends the results back over stderr for the purpose of parsing what you'd get otherwise for the Popen() results on stdout. You can also use the working directory option here, and set that first, as an alternate solution.

I think I included all the imports and defines that you'll need. If I missed any (copying and pasting spinets of source), let me know.

from os import system, getcwd, chdir
from subprocess import Popen, PIPE

import platform
__plat = platform.system()
IS_WINDOWS = __plat == "Windows"
IS_LINUX   = __plat == "Linux"
IS_MACOS   = __plat == "Darwin"

__SCRUB_CMD_TMPL = "{0}{1}"
__DBL_QUOTE      = '"'
__SPACE          = ' '
__ESC_SPACE      = '\\ '
if IS_WINDOWS :        
    __BATCH_RUN_AND_RETURN_CMD = ["cmd","/K"] # simply assuming cmd is on the system path... 
    __BATCH_ONE_LINER_TMPLT    = "{0} 1>&2\n" # the newline triggers execution when piped in via stdin
    __BATCH_ESCAPE_PATH_TMPLT  = 'for %A in ("{0}") do @echo %~sA' 
    from subprocess import STARTUPINFO, STARTF_USESHOWWINDOW
    __BATCH_ONE_LINER_STARTUPINFO = STARTUPINFO()
    __BATCH_ONE_LINER_STARTUPINFO.dwFlags |= STARTF_USESHOWWINDOW 

def _system( cmd, wrkDir=None ):
    if wrkDir is not None:
        initWrkDir = getcwd()
        print( 'cd "%s"' % (wrkDir,) )
        chdir( wrkDir  )
    cmd = __scrubSystemCmd( cmd )        
    print( cmd )
    system( cmd ) 
    print('')
    if wrkDir is not None: chdir( initWrkDir )

def __scrubSystemCmd( cmd ):
    """
    os.system is more convenient than the newer subprocess functions
    when the intention is to act as very thin wrapper over the shell. 
    There is just one MAJOR problem with it: 
    If the first character in the command is a quote (to escape a long path
    to the binary you are executing), then the limited (undesirable) parsing 
    built into the function can all fall apart.  So, this scrub function
    solves that...  
    """    
    if not cmd.startswith( __DBL_QUOTE ): return cmd
    cmdParts    = cmd[1:].split( __DBL_QUOTE )
    safeBinPath = _escapePath( cmdParts[0] )
    args        = __DBL_QUOTE.join( cmdParts[1:] ) # (the leading space will remain)
    return __SCRUB_CMD_TMPL.format( safeBinPath, args ) 

def _escapePath( path ):
    if not IS_WINDOWS: return path.replace(__SPACE, __ESC_SPACE)     
    return( path if __SPACE not in path else        
            __batchOneLinerOutput( __BATCH_ESCAPE_PATH_TMPLT.format(path) ) )    

def __batchOneLinerOutput( batch ):
    cmd = __BATCH_ONE_LINER_TMPLT.format( batch )
    p = Popen( __BATCH_RUN_AND_RETURN_CMD, shell=False, 
               startupinfo=__BATCH_ONE_LINER_STARTUPINFO,
               stdin=PIPE, stdout=PIPE, stderr=PIPE )    
    # pipe cmd to stdin, return stderr, minus a trailing newline
    return p.communicate( cmd )[1].rstrip()

回答5:

You can use the short name of the file which has spaces in its name.

file = 'C:\\Exe\\FirstV~1\\filename.exe'
os.system(file)

来源：https://stackoverflow.com/questions/6977215/os-system-to-invoke-an-exe-which-lies-in-a-dir-whose-name-contains-whitespace

标签

python

windowserror