Import python script with arguments

Question

I have scripts:

moving1.py:

def move():
 print("walk!")

moving2.py:

def move():
 print("run!")

And man.py, that can accept by argument parameter moving1 or moving2 script to act.

man.py:

import sys
if len(sys.argv) <= 1:
 exit("Too less arguments calling script")
__import__(sys.argv[1])
moving = sys.modules[sys.argv[1]]
def move():
 moving.move()

Now I have testman.py script, that have to test all variants of man.py execution:

testman.py

import man #and somehow add here as argument "moving1"
man.move()
import man #and somehow add here as argument "moving2"
man.move()

There exist a lot of similar questions, but they don't do exactly what I want. How can I add arguments to imported scripts? Problem is not to check

if __name__ = "__main__":

there, problem is to import script exactly with parameters I want. Is it possible?

• Jamie Cockburn: You can't just raise a string like that: "exceptions must be old-style classes or derived from BaseException, not unicode"
• msvalkon: Why does this separation exist? It would be far easier to have functions in the same file and just map a command line argument to a function.
• Arkady: @msvalkon it is just simple example. Imagine that movingN.py has 100 small functions and parameters, most of them are lambda or etc (so, that is config, but it is easier to keep config in .py style). It is much simpler to create 3-4 separated config files and pass them to man.py, then mix them all in one file that will be hard to manipulate. And I should split logic from movingN.py and man.py, because code in man.py shouldn't be changed, and code in movingN can be changed by administrator.
• msvalkon: Then I suggest you should use argparse to define the command line interface.
• Arkady: @msvalkon interesting stuff, but how can it help me move parameters from testman.py to man.py?

Answer 1

You should separate your argument handling code and your import code:

man.py

import sys
def move():
 moving.move()
def setup(module):
 global moving
 moving = __import__(module)
if __name__ == "__main__":
 if len(sys.argv) <= 1:
 exit("Too less arguments calling script")
 setup(sys.argv[1])

testman.py

import man
man.setup(<name>)
man.move()

However, this seems like a very odd way of acheiving what you are trying do do. Perhaps you could clarify your goals?

• Arkady: That will not work. At "import man" line Exception will be raised, because there will be no arguments.
• Jamie Cockburn: Whoops! Meant to move all the argument handling code... Fixed!
• Arkady: I will use it if there don't exist way to achieve that by parsing parameters to imported script as arguments, thank you!
• Jamie Cockburn: If you want a massive hack, you could just change the contents sys.argv in testman.py. I.e: put sys.argv[1] = 'moving1' before your import. However, if you want to import multiple times (as your original code shows) you'll need to reload(man) each time.
• Arkady: That looks like hacking, I believe solution have to be simpler and without such tricks.

Answer 2

If you are taking filename as command line argument and if you want to import it, then use imp load_source module.

import imp
module = imp.load_source("module.name", sys.argv[1])
#Then call the function
module.move()

Basically imp module helps to load the modules in run-time.

Hope this helps!

• Arkady: thank you, but if I modify testman.py this way: import imp man = imp.load_source("man", "moving1") Then it don't works. "File not found". If I add ".py". it still can't find "man.py" and whow me error: moving1.py:4: RuntimeWarning: Parent module 'man' not found while handling absolute import import logging
• user2109788: @Arkady In that case you will have to get the absolute path of the file(append the present working directory or get path from __FILE__) and pass that to load_source
• Arkady: even if I add os.path.dirname(os.path.abspath(file)) before filename, it still have problems. It looks like it wants absolute path for "import logging"...