[New-bugs-announce] [issue39125] Type signature of @property not shown in help()

[Nguyễn Gia Phong]

New submission from Nguyễn Gia Phong <vn.mcsinyx at gmail.com>:

Dear Maintainer,

I want to request a feature on the generative documentation of type-hinting.
As of December 2019, I believe there is no support for generating such
information in help().  For demonstration, I have this tiny piece of code

class Foo:
    @property
    def bar(self) -> int: return 42

    @bar.setter
    def bar(self, value: int) -> None: pass

    def baz(self, arg: float) -> str: pass

whose documentation on CPython 3.7.5 (on Debian testing amd64 if that matters)
is generated as

class Foo(builtins.object)
 |  Methods defined here:
 |  
 |  baz(self, arg: float) -> str
 |  
 |  ----------------------------------------------------------------------
 |  Data descriptors defined here:
 |  
 |  __dict__
 |      dictionary for instance variables (if defined)
 |  
 |  __weakref__
 |      list of weak references to the object (if defined)
 |  
 |  bar

I expect the documentation for bar to be as informative as bar, i.e. something
similar to ``bar: int''.  As pointed out by ChrisWarrick on freenode#python,
the annotations are already present, yet help() is not making use of them:

>>> Foo.bar.fget.__annotations__
{'return': <class 'int'>}
>>> Foo.bar.fset.__annotations__
{'value': <class 'int'>, 'return': None}

Have a Merry Christmas or other holiday of your choice,
Nguyễn Gia Phong

----------
assignee: docs at python
components: Documentation
messages: 358823
nosy: McSinyx, docs at python
priority: normal
severity: normal
status: open
title: Type signature of @property not shown in help()
type: enhancement
versions: Python 3.5, Python 3.6, Python 3.7, Python 3.8, Python 3.9

_______________________________________
Python tracker <report at bugs.python.org>
<https://bugs.python.org/issue39125>
_______________________________________