Incorrect interaction between argparse nargs='*' and choices #92445
Description
In the code below, it is valid to supply no arguments.
from argparse import ArgumentParser p = ArgumentParser() p.add_argument('dessert', nargs='*', choices=('cake', 'pie')) p.parse_args([]) However, the following error is generated:
usage: tmp5.py [-h] [{cake,pie} ...] tmp5.py: error: argument dessert: invalid choice: [] (choose from 'cake', 'pie') What is happening is that the empty list is being treated a value rather than a collection of values.