CODEWITHSUNDEEP
pythonsubprocess
Lisa
Lisa

Reputation: 4436

cannot pass arguments to python script when invoke from subprocess

I have searched SO but couldn't find an asnwer. I want to invoke a python script(child script) from another python script(main script). I cannot pass arguments from parent to child? I am expecting "subprocess launched: id1-id2" from the console. But what I am getting is "subprocess launched:test-default". The subprocess is using the default parameters instead of receiving parameters from the parent script.

# parent
import subprocess
subprocess.call(['python', 'child.py', 'id1', 'id2'])

# script name: child.py
def child(id, id2):
    print ('subprocess launched: {}-{}'.format(str(id), id2))

if __name__ == '__main__':
    main(id='test', id2='default')

Upvotes: 0

Views: 277

Answers (1)

willeM_ Van Onsem
willeM_ Van Onsem

Reputation: 477794

The parameters that you pass to a Python process are stored in sys.argv [Python-doc]. This is a list of parameters, that works a bit similar to $@ in bash [bash-man] for example.

Note that argv[0] is not the first parameter, but the name of the Python script you run, as is specified by the documentation:

argv[0] is the script name (it is operating system dependent whether this is a full pathname or not).

The remaining parameters are the parameters passed to the script.

You can thus rewrite your child.py to:

# script name: child.py
from sys import argv

def child(id, id2):
    print ('subprocess launched: {}-{}'.format(str(id), id2))

if __name__ == '__main__':
    child(id=argv[1], id2=argv[2])

Upvotes: 2

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