Conditional arguments in Python function call

Is there a way pass arguments conditionally in Python (I use Python 2.7)?

As an example, this code gives 2 or 3 arguments depending if the 3rd argument exists in a dictionary.

if "arg3" in my_dict:
    my_method(
        my_dict[arg1],
        my_dict[arg2],
        my_dict[arg3],
    )
else:
    my_method(
        my_dict[arg1],
        my_dict[arg2],
    )

I think it looks redundant to write it this way. I've seen some info on argparse, which I think would look like this:

import argparse

parser = argparse.ArgumentParser()
parser.add_argument(my_dict[arg1])
parser.add_argument(my_dict[arg2])
if arg3 in my_dict:
    parser.add_argument(my_dict[arg3])
args = parser.parse_args()

my_method(args)

I don't really like this method either, as it needs an import and is hard to read.

Is there a way to do something like:

my_method(
    my_dict[arg1],
    my_dict[arg2],
    my_dict[arg3] if arg3 in my_dict,
)

Or any other way I am missing, that would be simple and clean?