CODEWITHSUNDEEP
pythonbashshell
jin890
jin890

Reputation: 33

python calling custom function from bash shell

How can I call the custom-defined function in a python script from a bash shell?

I tried to use sys.argv[1], but not working properly.

for example,

import sys

if __name__=='__main__':
    try:
        func = sys.argv[1]
    except: func = None

def function1():
~~~~~~~~
return a

def function2():
~~~~~~~~
return b

here, I want to call the function 1 or function 2 by typing like

$ script.py function1

$ script.py function2

Upvotes: 3

Views: 487

Answers (4)

Radek
Radek

Reputation: 1630

I suggest to use argparse module: https://docs.python.org/3/library/argparse.html#module-argparse

You will thank yourself later.

For your case - since you need to call only 1 function at the time - you can use positional arguments:

import argparse

def function1():
    print("1")

def function2():
    print("2")

parser = argparse.ArgumentParser()

F_MAP = {'function1': function1,
         'function2': function2}

parser.add_argument('function', choices=F_MAP.keys())

args = parser.parse_args()

F_MAP[args.function]()

As a bonus you get a nice help page when calling with -h argument :)

Upvotes: 3

AlokThakur
AlokThakur

Reputation: 3741

You can refer Display a list of user defined functions in the Python IDLE session

import types
list_function = [f for f in globals().values() if type(f) == types.FunctionType]

This will return list of available functions, Then you can check if any of these contain sys.argv[1], If yes then you can call your function as 

list_function[index]()

Upvotes: 1

art-solopov
art-solopov

Reputation: 4755

@bigOTHER's answer is good and correct, but if you're looking to build a relatively complex text UI, maybe have a look at something like Click?

Upvotes: 1

Assem
Assem

Reputation: 12087

You are getting the name of function , but you are not running it. You should check first if the func name is one of your functions than execute it:

if __name__=='__main__':
    try:
        func = sys.argv[1]
    except: 
        func = None

functions = {    
              "function1": function1,
              "function2": function2
              }

if func in functions:
    functions[func]()

A simpler solution:

 if func == "function1":
     function1()
 elif func == "function2":
     function2()

Upvotes: 6

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