Passing arguments to a Python script

Question

I want to pass arguments to a Python script in two ways,

python main.py --source=aws

and

python main.py source aws

This is my current code,

parser = argparse.ArgumentParser()
parser.add_argument("--s", "--source", help='Flag to choose source')

This makes the first option possible. How do I make the second option possible?

• chepner: What is the benefit of providing both ways? There's no clean, simple way to support both.
• hpaulj: The current code also allows: python main.py --source aws.

Answer 1

There is not a way to do that with Argparse. The only way to do that is by filtering stdin using sys.argv.

import argparse
import sys
mangle_my_args = ['s', 'source']
arguments=['--'+arg if arg in mangle_my_args else arg for arg in sys.argv[1:]]
parser = argparse.ArgumentParser()
parser.add_argument("--s", "--source", help='Flag to choose source')
print(parser.parse_args(arguments))