From 14092b5a4ae4caf1c77f685450016a0d1ad0bd6c Mon Sep 17 00:00:00 2001 From: Raymond Hettinger Date: Thu, 22 Apr 2021 17:53:36 -0700 Subject: bpo-43917: Fix pure python equivalent for classmethod (GH-25544) Reported by Yahor Harunovich. --- Doc/howto/descriptor.rst | 13 ++++++++++++- Misc/ACKS | 3 ++- 2 files changed, 14 insertions(+), 2 deletions(-) diff --git a/Doc/howto/descriptor.rst b/Doc/howto/descriptor.rst index bf026f4..074591f 100644 --- a/Doc/howto/descriptor.rst +++ b/Doc/howto/descriptor.rst @@ -1329,7 +1329,7 @@ Using the non-data descriptor protocol, a pure Python version of def __get__(self, obj, cls=None): if cls is None: cls = type(obj) - if hasattr(obj, '__get__'): + if hasattr(type(self.f), '__get__'): return self.f.__get__(cls) return MethodType(self.f, cls) @@ -1342,6 +1342,12 @@ Using the non-data descriptor protocol, a pure Python version of def cm(cls, x, y): return (cls, x, y) + @ClassMethod + @property + def __doc__(cls): + return f'A doc for {cls.__name__!r}' + + .. doctest:: :hide: @@ -1353,6 +1359,11 @@ Using the non-data descriptor protocol, a pure Python version of >>> t.cm(11, 22) (, 11, 22) + # Check the alternate path for chained descriptors + >>> T.__doc__ + "A doc for 'T'" + + The code path for ``hasattr(obj, '__get__')`` was added in Python 3.9 and makes it possible for :func:`classmethod` to support chained decorators. For example, a classmethod and property could be chained together: diff --git a/Misc/ACKS b/Misc/ACKS index e394ea6..760d6c7 100644 --- a/Misc/ACKS +++ b/Misc/ACKS @@ -388,7 +388,7 @@ Brian Curtin Jason Curtis Hakan Celik Paul Dagnelie -Florian Dahlitz +Florian Dahlitz Lisandro Dalcin Darren Dale Andrew Dalke @@ -694,6 +694,7 @@ Michael Haubenwallner Janko Hauser Flavian Hautbois Rycharde Hawkes +Yahor Harunovich Ben Hayden Jochen Hayek Tim Heaney -- cgit v0.12