如何在python 2.x交互模式下将参数传递给模块

Question

I'm using Python 2.7, and I have the following simple script, which expects one command line argument:

#!/usr/bin/env python

import sys

if (len(sys.argv) == 2):
   print "Thanks for passing ", sys.argv[1]
else:
   print "Oops."

I can do something like this from the command line:

My-Box:~/$ ./useArg.py asdfkjlasdjfdsa
    Thanks for passing  asdfkjlasdjfdsa

or this:

My-Box:~/$ ./useArg.py 
    Oops.

I would like to do something similar from the interactive editor:

>>> import useArg asdfasdf
  File "<stdin>", line 1
    import useArg asdfasdf
                         ^
SyntaxError: invalid syntax

but I don't know how. How can I pass a parameters to import/reload in the interactive editor ?

Answer 1

You can't. Wrap your code inside the function

#!/usr/bin/env python

import sys

def main(args):
    if (len(args) == 2):
        print "Thanks for passing ", args[1]
    else:
        print "Oops."

if __name__ == '__main__':
    main(sys.argv)

If you execute your script from command line you can do it like before, if you want to use it from interpreter:

import useArg
useArg.main(['foo', 'bar'])

In this case you have to use some dummy value at the first position of the list, so most of the time much better solution is to use argparse library . You can also check the number of command line arguments before calling the main function:

import sys

def main(arg):
    print(arg)

if __name__ == '__main__':
    if len(sys.argv) == 2:
        main(sys.argv[1])
    else:
        main('Oops') 

You can find good explanation what is going on when you execute if __name__ == '__main__': here: What does if __name__ == "__main__": do?