Question. How to use switches together with environment variables?

[Ilya Golshtein]

Hello,
I have simple command line flags, that perfectly work with action="store_true".
I would like to have it controlled via environment as well, but it does not work well.

Ideally I want to specify
myscript --debug or DEBUG=true myscript and it works indeed,
unless I try DEBUG=false myscript. The latest one is converted to True as well.

The question is what is the best way to achieve the goal.

Switching to type=bool works, but not convenient as for commandline. Attempt to have two parameters with same dest is not successful (obviously).

[Ilya Golshtein]

My bad, the attempt to have two parameters with same dest IS successful.
I have

parser.add_argument(
    "--silent",
    action="store_true",
    dest="silent_flag",
    default=False,
    help="no log"
)
parser.add_argument(
    "--silentflag",
    "--silent-flag",
    dest="silent_flag",
    type=bool,
    default=False,
    help="no log"
)