Python Argparse: Use an empty flag

Question

I'm trying to write a python script using argparse which sets a value to True if -d has been set.

Here is what I'm trying:

parser.add_argument("-d", "--dynamic", required=False)

dynamic = False
if args.dynamic is not None:
  dynamic = True

I get the following error:

usage: psd.py [-h] -f FILE [-d DYNAMIC] psd.py: error: argument -d/--dynamic: expected one argument

How do I set the flag to expect 0 arguments?

Answer 1

Use the action:

parser.add_argument("-d", "--dynamic", action='store_true')

You may drop the "required" kwarg.