Message 384760 - Python tracker

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Author	larry
Recipients	eric.smith, gvanrossum, larry
Date	2021-01-10.11:29:52
SpamBayes Score	-1.0
Marked as misclassified	Yes
Message-id	<1610278192.15.0.512262305909.issue42881@roundup.psfhosted.org>
In-reply-to

Content
PEP 484 says: (Note that the return type of __init__ ought to be annotated with -> None. The reason for this is subtle. [...] https://www.python.org/dev/peps/pep-0484/#the-meaning-of-annotations If you follow this advice, then call typing.get_type_hints() on your __init__ function, you'll find it has turned "None" into "type(None)". git blame suggests get_type_hints' behavior was in the initial checkin of typing.py (46dbb7d1032c19163f37785509b8f5b3004416e8). So it's always behaved this way. Is "None" still considered the correct return annotation of an __init__? If so, should typing.get_type_hints() really be changing it to type(None)?

PEP 484 says:

    (Note that the return type of __init__ ought to be annotated
     with -> None. The reason for this is subtle. [...]

    https://www.python.org/dev/peps/pep-0484/#the-meaning-of-annotations

If you follow this advice, then call typing.get_type_hints() on your __init__ function, you'll find it has turned "None" into "type(None)".

git blame suggests get_type_hints' behavior was in the initial checkin of typing.py (46dbb7d1032c19163f37785509b8f5b3004416e8).  So it's always behaved this way.

Is "None" still considered the correct return annotation of an __init__?  If so, should typing.get_type_hints() really be changing it to type(None)?

History
Date	User	Action	Args
2021-01-10 11:29:52	larry	set	recipients: + larry, gvanrossum, eric.smith
2021-01-10 11:29:52	larry	set	messageid: <1610278192.15.0.512262305909.issue42881@roundup.psfhosted.org>
2021-01-10 11:29:52	larry	link	issue42881 messages
2021-01-10 11:29:52	larry	create