CODEWITHSUNDEEP
pythonargumentsargparse
technillogue
technillogue

Reputation: 1571

Can you pass keyword arguments instead of positional arguments to argparse?

Suppose you have a python function, as so:

def foo(spam, eggs, ham):
    pass

You could call it using the positional arguments only (foo(1, 2, 3)), but you could also be explicit and say foo(spam=1, eggs=2, ham=3), or mix the two (foo(1, 2, ham=3)).

Is it possible to get the same kind of functionality with argparse? I have a couple of positional arguments with keywords, and I don't want to define all of them when using just one.

Upvotes: 4

Views: 3587

Answers (3)

swietyy
swietyy

Reputation: 834

You can also use this module: docopt

Upvotes: 1

mgilson
mgilson

Reputation: 310097

You can do something like this:

import argparse
parser = argparse.ArgumentParser()
parser.add_argument('foo',nargs='?',default=argparse.SUPPRESS)
parser.add_argument('--foo',dest='foo',default=None)

parser.add_argument('bar',nargs='?',default=argparse.SUPPRESS)
parser.add_argument('--bar',dest='bar',default=None)

parser.add_argument('baz',nargs='?',default=argparse.SUPPRESS)
parser.add_argument('--baz',dest='baz',default=None)

print parser.parse_args()

which works mostly as you describe:

temp $ python test.py 1 2 --baz=3
Namespace(bar='2', baz='3', foo='1')
temp $ python test.py --baz=3
Namespace(bar=None, baz='3', foo=None)
temp $ python test.py --foo=2 --baz=3
Namespace(bar=None, baz='3', foo='2')
temp $ python test.py 1 2 3
Namespace(bar='2', baz='3', foo='1')

python would give you an error for the next one in the function call analogy, but argparse will allow it:

temp $ python test.py 1 2 3 --foo=27.5
Namespace(bar='2', baz='3', foo='27.5')

You could probably work around that by using mutually exclusive groupings

Upvotes: 6

Tuim
Tuim

Reputation: 2511

I believe this is what you are looking for Argparse defaults

Upvotes: 0

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