Inconsistency in json.JSONEncoder Description Regarding skipkeys Behavior

If skipkeys is false (the default), a TypeError will be raised when trying to encode keys that are not str, int, float or None. If skipkeys is true, such items are simply skipped.

However, boolean values (True and False) can be used as dictionary keys without raising a TypeError. I think this is a mistake.

json.JSONEncoder(skipkeys=False).encode({True:1})

Linked PRs

gh-132021: Add bool type to the list of allowed JSON key types #132048
[3.13] gh-132021: Add bool type to the list of allowed JSON key types (GH-132048) #132255
[3.12] gh-132021: Add bool type to the list of allowed JSON key types (GH-132048) #132256

bools are ints, so the statement is technically true.

>>> isinstance(True, int)
True
>>> isinstance(False, int)
True

Although maybe it makes sense to add bool to the list of types.

Thank you, I understand. I noticed that the description of json.dump includes bool. It would be better to keep it consistent.

skipkeys (bool) – If True, keys that are not of a basic type (str, int, float, bool, None) will be skipped instead of raising a TypeError. Default False.

Seems good - would you like to put up a PR?

pythongh-132021: Add bool type to the list of types that were allowed…

Merge branch 'main' into pythongh-132021

gh-132021: Add bool type to the list of allowed JSON key types (#132048)

pythongh-132021: Add bool type to the list of allowed JSON key types (p…

[3.12] gh-132021: Add bool type to the list of allowed JSON key types (…

[3.13] gh-132021: Add bool type to the list of allowed JSON key types (…

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Inconsistency in json.JSONEncoder Description Regarding skipkeys Behavior #132021

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Inconsistency in json.JSONEncoder Description Regarding skipkeys Behavior #132021

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ericvsmith commented on Apr 2, 2025

mouchen626 commented on Apr 2, 2025

brianschubert commented on Apr 2, 2025

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