gh-103498: argparse.ArgumentParser will always throw instead of exit if exit_on_error=False

[JustBeYou]

Fix for #103498

Summary:

• moved the decision of if we should raise exception or exit to ArgumentParser.error method based on exit_on_error parameter
• replaced all raise ArgumentError with self.error() in ArgumentParser
• added a new named parameter to ArgumentParser.error, namely action=None because raising ArgumentError requires it
• updated the documentation to reflect the change

Note:

• adding a new named parameter breaks the API for classes that inherit ArgumentParser; a solution to this would be to use **kwargs instead, but seems kind of dirty to me. suggestions appreciated

• Issue: argparse exits on error even when exit_on_error=False #103498

[bedevere-bot]

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[ghost]

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[olgarithms]

@sobolevn , do you think this is a good fix? I can add tests to this :)

[JustBeYou]

Taking a closer look at the problem, I don't see the proposed fix as suitable anymore. I think that to properly solve the problem with exit_on_error, we have to address the inconsistent error handling in ArgumentParser (raising and calling self.error in multiple places). I will share some opinions on the associated issue, maybe we could move forward somehow.

[serhiy-storchaka]

Thank you for your contribution @JustBeYou. I apologize for the fact that this PR was neglected for a long time. The problem has already been solved in another way.