subprocess call cannot find the file specified

[RRR]

Hi,
I am trying to launch a batch file in windows with some arguments from a different directory.
Well its working with

1

os.system

call, as its a straight forward way.
But i want to use

1	subprocess.call

in order to have better control of result.

If i use command

test.bat -file_arg=drawings/mydrawings.cfg

it works, but through python program its gives the error.

Please let me know what i am missing

Output:
C:\Users\Projects>C:\Python27\python.exe fp_subprocess.py
CWD: C:\Users\Projects
BAT DIR C:\\MyWork\\Temp\\
script DIR test.bat -file=drawings/mydrawings.cfg

Traceback (most recent call last):
  File "fp_subprocess.py", line 28, in <module>
    if True == launch_BAT():
  File "fp_subprocess.py", line 14, in launch_BAT
	subprocess.call(["test.bat"+" -file="+TESTCFG_PATH])
  File "C:\Python27\lib\subprocess.py", line 172, in call
    return Popen(*popenargs, **kwargs).wait()
  File "C:\Python27\lib\subprocess.py", line 394, in __init__
    errread, errwrite)
  File "C:\Python27\lib\subprocess.py", line 644, in _execute_child
    startupinfo)
WindowsError: [Error 2] The system cannot find the file specified

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

def launch_BAT():     TESTBAT_PATH = b'C:\\MyWork\\Temp\\'     TESTCFG_PATH = b'drawings/mydrawings.cfg'# also tried 'drawings\\mydrawings.cfg'     print "CWD:", os.getcwd()     os.chdir(TESTBAT_PATH)     print "BAT DIR", os.getcwd()     print "script DIR", "test.bat"+" -file="+TESTCFG_PATH     print           subprocess.call(["test.bat"+" -file="+TESTCFG_PATH])       if __name__ == "__main__":     if True == launch_BAT():         print "**launch_BAT Successful**"     else:         print "**launch_BAT UnSuccessful**"

[buran]

Instead of changing the CWD why not just pass fullpath?
No need to conatenate str in subprocess call

1 2 3 4 5

import os def launch_BAT():     TESTBAT_PATH = r'C:\MyWork\Temp\'     TESTCFG_PATH = r'drawings\mydrawings.cfg'     subprocess.run(["test.bat", f"-file={os.path.join(TESTBAT_PATH, TESTCFG_PATH)}"])

* code not tested
Note that your function will return None, so True/False checks you do will not work and in any case (assuming at some point the function start to return something else) if launch_BAT(): is better than comparing with True - True == launch_BAT().

Also it's better if your function has params and you pass paths as arguments, instead of having hardcoded paths.

[RRR]

Instead of changing the CWD why not just pass fullpath?

No, the script is designed in such a way that it accepts only relative path, it does not work if we pass full path.

Also it's better if your function has params and you pass paths as arguments, instead of having hardcoded paths.

Its just a minimal code to reproduce the problem.

[buran]

by the way I just now noticed you are using python 2.7. Some of changes I made will not work for version prior 3.6

[RRR]

by the way I just now noticed you are using python 2.7. Some of changes I made will not work for version prior 3.6

Yes its giving Invalid synatax at the last double quote in

1	subprocess.call

How can i safety launch .bat file as per my requirement.

[yaythomas]

Use the cwd input on your sub-process method.

1	subprocess.run("exit 1", shell=True, check=True, cwd='./directory-here')

check out the docs for full info here: https://docs.python.org/3/library/subprocess.html

Note that call is an old/retired function, if you're on Python 3 or higher you probably want to use .run instead.

[RRR]

Use the cwd input on your sub-process method.

1	subprocess.run("exit 1", shell=True, check=True, cwd='./directory-here')

check out the docs for full info here: https://docs.python.org/3/library/subprocess.html

Note that call is an old/retired function, if you're on Python 3 or higher you probably want to use .run instead.

Nooo yaythomas,

please give me something which works on Python 2.7