==== --feature and --no-feature ====
To do
<code>
command --feature
</code>
and
<code>
command --no-feature
</code>

For python >= 3.9:
<code>
parser.add_argument('--feature', action=argparse.BooleanOptionalAction)
</code>

For python < 3.9:
<code>
parser.add_argument('--feature', action='store_true')
parser.add_argument('--no-feature', dest='feature', action='store_false')
parser.set_defaults(feature=True)
</code>

In practice:
<code>
parser.add_argument(
    "--header", action='store_true',
    dest='header',
    help='use 1st line as header')
parser.add_argument(
    "--no-header", action='store_false',
    dest='header',
    help='assumes that there is no header')
parser.set_defaults(header=True)
</code>

Ref:-
  * https://stackoverflow.com/questions/15008758/parsing-boolean-values-with-argparse
  * https://docs.python.org/3/library/argparse.html#action -> search for ''<nowiki>--no-foo</nowiki>''