Loris Bennett wrote:
> "Loris Bennett" <[email protected]> writes:
>
>> Hi,
>>
>> I am writing a program for the command-line which uses 'argsparse'. I
>> want to make some options mandatory by setting 'required=True', but
>> still allow the program to run with the option '--version' (which just
>> shows the version and then exits) even if the mandatory options are
>> missing.
>>
>> Is there a standard way of doing this?
>
> I see that instead of setting required to 'True' I can use an expression
> which checks whether '--version' has been given:
What I do is separate it into two functions. First function that sets up
the parser object and returns the parser object:
def make_parser() -> argparse.ArgumentParser:
parser = argparse.ArgumentParser( ... )
...
return parser
The code is similar to yours below, but for version my action references
an f string variable:
parser.add_argument(
"-v", "--version", action="version",
version=f"{APP_NAME} v{__version__}"
)
I typically have the optional args set to a default value, null string
or None. Then the second function which my main() calls this function
which returns a tuple of arg values here is one example:
def get_program_args() -> tuple:
parser = make_parser()
args = parser.parse_args()
return args.action, args.profile, args.log_level
def main():
# parser args
action, profile_name, log_level = get_program_args()
...
Works for me.
> parser.add_argument(
> "uid", nargs="+",
> help="UIDs to send mail to"
> )
> parser.add_argument(
> '-s', '--subject', dest='subject', required=not '--version' in
> sys.argv,
> help="subject of email"
> )
> parser.add_argument(
> '-c', '--content_file', dest='content_file', required=not '--version'
> in sys.argv,
> help="file containing mail contents (without salutation or signature)"
> )
> parser.add_argument(
> '--version', action='store_true', dest='version',
> help="print version"
>
> However, with the above, I still need to specify the mandatory argument,
> even if I only want to see the version.
>
> I guess I'll just have to change
>
> nargs="+"
>
> to
>
> nargs="*"
>
> and check explicitly whether any arguments have been given.
>
> Seems odd to me though that there is not a standard way of implementing
> '--version' which works like '--help' does.
>
> Cheers,
>
> Loris
>
--
Take care,
Jonathan
-------------------
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http://www.LittleWorksStudio.com
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