Bug report

When running a command line program with the--help/-h flag withargparse, if another flag has multiple names and choices to pick from, the options are printed multiple times instead of just once. For example, the program below:

importargparseif__name__=="__main__":parser=ArgumentParser()parser.add_argument('-m','--metric',choices=["accuracy","precision","recall"])parser.parse_args(["-h"])

Will print

usage: argparse_test.py [-h] [-m {accuracy,precision,recall}]options:  -h, --help            show thishelp message andexit  -m {accuracy,precision,recall}, --metric {accuracy,precision,recall}

Notice that the flag choices are printed out twice, once for each flag name. This is redundant and negatively impacts readability. The program should output:

usage: argparse_test.py [-h] [-m {accuracy,precision,recall}]options:  -h, --help            show thishelp message andexit  -m, --metric {accuracy,precision,recall}

Your environment

• CPython versions tested on: 3.10.6
• Operating system and architecture: Windows 11 with WSL 2

Linked PRs

• gh-101599: changed argparse -h/-help flag for the sake of readability #103372
• GH-101599: Update docs to remove redundant option in argparse tutorial #124025
• [3.12] GH-101599: Update docs to remove redundant option in argparse tutorial (GH-124025) #124036
• [3.13] GH-101599: Update docs to remove redundant option in argparse tutorial (GH-124025) #124037