Suggestion for argparse: raise a warning on type=bool

[user202729]

Feature or enhancement

Proposal:

There has been complaints about type=bool usage in argparse: #81745 #83348 #71181 . See also https://stackoverflow.com/questions/15008758/parsing-boolean-values-with-argparse

while we may not want to actually change the behavior (given existing code on the wild might use it, as mentioned in previous discussions), what about raise a warning? Or is that also too intrusive?

Has this already been discussed elsewhere?

No response given

Links to previous discussion of this feature:

No response

Linked PRs

• gh-126676: Expand argparse docs for type=bool with warning and alternatives #146435
• [3.14] gh-126676: Expand argparse docs for type=bool with warning and alternatives (GH-146435) #148048
• [3.13] gh-126676: Expand argparse docs for type=bool with warning and alternatives (GH-146435) #148049

[savannahostrowski]

I'd probably be more inclined to document recipes/patterns to achieve the desired result if we need additional materials here since we have already documented that bool() is not recommended as a type converter.

The bool() function is not recommended as a type converter. All it does is convert empty strings to False and non-empty strings to True. This is usually not what is desired.

My concern is that adding a warning here could still break tests, etc.