Python argparse: Mutually exclusive group with some compatible arguments
argparse, python
Solution
You could not really do it with `argparse`, however you can do it after `argparse` has run.
Here is an example:
parser = argparse.ArgumentParser()
# group 1
parser.add_argument("-q", "--query", help="query", required=False)
parser.add_argument("-f", "--fields", help="field names", required=False)
# group 2
parser.add_argument("-a", "--aggregation", help="aggregation",
required=False)
I am using here options given to a command line wrapper for querying a mongodb. The `collection` instance can either call the method `aggregate` or the method `find` with to optional arguments `query` and `fields`, hence you see why the first two arguments are compatible and the last one isn't.
So now I run `parser.parse_args()` and check it's content:
args = parser().parse_args()
print args.aggregation
if args.aggregation and (args.query or args.fields):
print "-a and -q|-f are mutually exclusive ..."
sys.exit(2)
Of course, this little hack is only working for simple cases and it would become a nightmare to check all the possible options if you have many mutually exclusive options and groups. In that case you should break your options in to command groups. For that, you should follow the suggestion here Python argparse mutual exclusive group.
Problem
I would like to implement logic like this in argparse: ``` If argument A is selected, the user cannot select arguments B or C. B and C can both be selected ``` It looks like `add_mutually_exclusive_group` is what I would want for this, but it looks like you can only choose one option from a mutually exclusive group, so I cannot put all three in a mutually exclusive group. Is there a way to do this in argparse?