Question: I'm trying to figure out how to use properly builtin argparse module to get a similar output than tools such as git where I can display a nice help with all "root commands" nicely grouped, ie: $ git --help usage: git [--version] [--help] [-C <path>] [-c <name>=<value>] [--exec-path[=<path>]] [--html-path] [--man-path] [--info-path] [-p | --paginate | -P | --no-pager] [--no-replace-objects] [--bare] [--git-dir=<path>] [--work-tree=<path>] [--namespace=<name>] [--super-prefix=<path>] [--config-env=<name>=<envvar>] <command> [<args>] These are common Git commands used in various situations: start a working area (see also: git help tutorial) clone Clone a repository into a new directory init Create an empty Git repository or reinitialize an existing one work on the current change (see also: git help everyday) add Add file contents to the index mv Move or rename a file, a directory, or a symlink restore Restore working tree files rm Remove files from the working tree and from the index examine the history and state (see also: git help revisions) bisect Use binary search to find the commit that introduced a bug diff Show changes between commits, commit and working tree, etc grep Print lines matching a pattern log Show commit logs show Show various types of objects status Show the working tree status grow, mark and tweak your common history branch List, create, or delete branches commit Record changes to the repository merge Join two or more development histories together rebase Reapply commits on top of another base tip reset Reset current HEAD to the specified state switch Switch branches tag Create, list, delete or verify a tag object signed with GPG collaborate (see also: git help workflows) fetch Download objects and refs from another repository pull Fetch from and integrate with another repository or a local branch push Update remote refs along with associated objects 'git help -a' and 'git help -g' list available subcommands and some concept guides. See 'git help <command>' or 'git help <concept>' to read about a specific subcommand or concept. See 'git help git' for an overview of the system.  Here's my attempt: from argparse import ArgumentParser class FooCommand: def __init__(self, subparser): self.name = "Foo" self.help = "Foo help" subparser.add_parser(self.name, help=self.help) class BarCommand: def __init__(self, subparser): self.name = "Bar" self.help = "Bar help" subparser.add_parser(self.name, help=self.help) class BazCommand: def __init__(self, subparser): self.name = "Baz" self.help = "Baz help" subparser.add_parser(self.name, help=self.help) def test1(): parser = ArgumentParser(description="Test1 ArgumentParser") root = parser.add_subparsers(dest="command", description="All Commands:") # Group1 FooCommand(root) BarCommand(root) # Group2 BazCommand(root) args = parser.parse_args() print(args) def test2(): parser = ArgumentParser(description="Test2 ArgumentParser") # Group1 cat1 = parser.add_subparsers(dest="command", description="Category1 Commands:") FooCommand(cat1) BarCommand(cat1) # Group2 cat2 = parser.add_subparsers(dest="command", description="Category2 Commands:") BazCommand(cat2) args = parser.parse_args() print(args)  If you run test1 you'd get: $ python mcve.py --help usage: mcve.py [-h] {Foo,Bar,Baz} ... Test1 ArgumentParser options: -h, --help show this help message and exit subcommands: All Commands: {Foo,Bar,Baz} Foo Foo help Bar Bar help Baz Baz help  Obviously this is not what I want, in there I just see all commands in a flat list, no groups or whatsoever... so the next logical attempt would be trying to group them. But if I run test2 I'll get: $ python mcve.py --help usage: mcve.py [-h] {Foo,Bar} ... mcve.py: error: cannot have multiple subparser arguments  Which obviously means I'm not using properly argparse to accomplish the task at hand. So, is it possible to use argparse to achieve a similar behaviour than git? In the past I've relied on "hacks" so I thought the best practice here would be using the concept of add_subparsers but it seems I didn't understand properly that concept.

Answer: This isn't supported natively by argparse -- you can't nest subparsers, so if you want this sort of cli using argparse you're going to need to build a lot of logic on top of argparse. You can set nargs=argparse.REMAINDER to collect a subcommand and arguments without having them parsed by argparse, which means we can build something like this: import argparse import copy class Command: def __init__(self): self.subcommands = {} self.parser = argparse.ArgumentParser() def add_subcommand(self, name, sub): self.subcommands[name] = sub def add_argument(self, *args, **kwargs): return self.parser.add_argument(*args, **kwargs) def parse_args(self, args=None): if not self.subcommands: args = self.parser.parse_args(args) return args p = copy.deepcopy(self.parser) p.add_argument("subcommand") p.add_argument("args", nargs=argparse.REMAINDER) args = p.parse_args(args) try: sub = self.subcommands[args.subcommand] except KeyError: return self.parser.parse_args(args) sub_args = sub.parse_args(args.args) for attr in dir(sub_args): if attr.startswith("_"): continue setattr(args, attr, getattr(sub_args, attr)) return args def main(): root = Command() root.add_argument("-v", "--verbose", action="count") cmd1 = Command() cmd1_foo = Command() cmd1_foo.add_argument("-n", "--name") cmd1.add_subcommand("foo", cmd1_foo) root.add_subcommand("cmd1", cmd1) cmd2 = Command() cmd2_bar = Command() cmd2_bar.add_argument("-s", "--size", type=int) cmd2.add_subcommand("bar", cmd2_bar) root.add_subcommand("cmd2", cmd2) print(root.parse_args()) if __name__ == "__main__": main()  This is horrible and ugly and poorly structured, but it means we can do this: $ python argtest.py --verbose cmd1 foo --name lars Namespace(verbose=1, subcommand='foo', args=['--name', 'lars'], name='lars')  Or this: $ python argtest.py --verbose cmd2 bar --size 10 Namespace(verbose=1, subcommand='bar', args=['--size', '10'], size=10)   If you're willing to look beyond argparse, libraries like Click and Typer make things much easier. For example, the above command could be implemented using Click like this: import click @click.group() def main(): pass @main.group() def cmd1(): pass @cmd1.command() @click.option('-n', '--name') def foo(name): pass @main.group() def cmd2(): pass @cmd2.command() @click.option('-s', '--size', type=int) def bar(): pass if __name__ == '__main__': main()  So much nicer!