classification
Title: ArgumentParser nested subparsers resolve paths in improper order
Type: behavior Stage:
Components: Versions: Python 3.10, Python 3.9, Python 3.8
process
Status: open Resolution:
Dependencies: Superseder:
Assigned To: Nosy List: carsonwilber, rhettinger
Priority: normal Keywords:

Created on 2020-11-25 04:36 by carsonwilber, last changed 2020-11-25 06:13 by izbyshev.

Messages (1)
msg381789 - (view) Author: Carson Wilber (carsonwilber) Date: 2020-11-25 04:36
ArgumentParser improperly resolves arguments in an improper order when using nested subparsers if there are required arguments at more than one layer.

A minimum viable reproduction is to create a set of subparsers on a primary parser, and a set of subparsers on at least one of those parsers. On the main parser and the first-level subparser, add a required argument (in any position as they are appended to the end.)

If you attempt to, for example, print the help for a second-level subparser, an error will be thrown and the parser will exit due to the required argument(s) not being provided, despite the expected behavior and the nature of the -h flag not requiring those arguments to be provided.

For lack of an appropriate means to show a complete minimum viable reproduction here, please see this StackOverflow thread I initially created believing this to be user error (having now determined this is a bug in behavior):

https://stackoverflow.com/questions/64908447/printing-help-for-nested-subparsers-with-required-positional-arguments
History
Date User Action Args
2020-11-25 06:13:00izbyshevsetnosy: + rhettinger

versions: - Python 3.6, Python 3.7
2020-11-25 04:36:54carsonwilbercreate