gh-99735: Handle no arguments when using sub-commands in argparse

[ppaez]

This provides a fix to improve the example in the documentation.

• Issue: Handle no arguments when using sub-commands in argparse #99735

[cpython-cla-bot]

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[slateny]

I'd recommend keeping the original structure so just the new changes can be more easily reviewed.

Suggested change

	One particularly effective way of handling sub-commands is to
	combine the use of the :meth:`add_subparsers` method with calls to
	:meth:`set_defaults` so that each subparser knows which Python
	function it should execute. The :meth:`set_defaults` method of the
	One particularly effective way of handling sub-commands is to combine the use
	of the :meth:`add_subparsers` method with calls to :meth:`set_defaults` so
	that each subparser knows which Python function it should execute.
	The :meth:`set_defaults` method of the

[slateny]

tiny nit, since 'sub-command' was used above in the same paragraph

Suggested change

	main parser is called to handle the case when no subcommand is
	main parser is called to handle the case when no sub-command is

[hauntsaninja]

Thanks! Closing in favour of #100927