docs.python.org/3/howto/descriptor.html still refers to "unbound methods"

[pfalcon]

BPO	23702
Nosy	@rhettinger, @pfalcon, @gpshead, @ezio-melotti, @stevendaprano, @vadmium
PRs	bpo-23702: Update Descriptor-HOWTO to reflect the removal of unbound … #3739 [3.6] bpo-23702: Update Descriptor-HOWTO to reflect the removal of unbound methods (GH-3739) #3742

^{Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.}

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GitHub fields:

assignee = 'https://github.com/rhettinger'
closed_at = <Date 2017-09-25.08:16:07.622>
created_at = <Date 2015-03-18.19:48:34.439>
labels = ['type-bug', 'docs']
title = 'docs.python.org/3/howto/descriptor.html still refers to "unbound methods"'
updated_at = <Date 2017-09-25.08:16:07.622>
user = 'https://github.com/pfalcon'

bugs.python.org fields:

activity = <Date 2017-09-25.08:16:07.622>
actor = 'rhettinger'
assignee = 'rhettinger'
closed = True
closed_date = <Date 2017-09-25.08:16:07.622>
closer = 'rhettinger'
components = ['Documentation']
creation = <Date 2015-03-18.19:48:34.439>
creator = 'pfalcon'
dependencies = []
files = []
hgrepos = []
issue_num = 23702
keywords = ['patch']
message_count = 9.0
messages = ['238468', '253167', '293220', '293221', '299738', '299739', '299753', '302918', '302920']
nosy_count = 8.0
nosy_names = ['rhettinger', 'pfalcon', 'gregory.p.smith', 'ezio.melotti', 'steven.daprano', 'docs@python', 'martin.panter', 'Johannes Lade']
pr_nums = ['3739', '3742']
priority = 'normal'
resolution = 'fixed'
stage = 'resolved'
status = 'closed'
superseder = None
type = 'behavior'
url = 'https://bugs.python.org/issue23702'
versions = ['Python 3.5', 'Python 3.6']

[pfalcon]

Under https://docs.python.org/3/howto/descriptor.html#functions-and-methods , there're several references to unbound methods (including in expected output from the interpreter).

As known, unbound methods are gone in Python3, so seeing those are confusing. (I didn't sharply know that unbound methods are gone from Py3, so was pretty confused by the examples there, comparing them with actual output of Cpython 3.4).

[vadmium]

Current patch for bpo-25435 addresses the code example. Changes to the text are also needed though.

[stevendaprano]

Be careful with the documentation patch. Although unbound method as an object type is gone, unbound method as a concept is not.

Conceptually, something like MyClass.spam is an unbound method: it is a method of the MyClass type, but bound to no instance. In Python 2 that concept was implemented by MethodType. In Python 3, the concept is implemented by FunctionType.

While it is certainly true from one perspective that unbound methods are nothing but functions, it is nevertheless also sometimes useful to distinguish from "functions defined in a class" (methods) and "other functions". I think that nearly all Python programmers would be happy to call spam below:

    class MyClass:
        def spam(self, arg): ...

a method, even though it is also/really a function.

[rhettinger]

I'll fix that up. I've already been working on revising the document. There are a number of updates needed (user-friendly intro, properties revised to show the setting methods, __set_name__, etc).

[JohannesLade]

This is still a problem. Can please somebody fix this? There are already enough confusing discussion full of wrong information about this topic, so it would be nice if the official documentation would get it right. Also there's multiple Issues for this. Can they be combined into one?
Just one example I found: on https://docs.python.org/3.5/howto/descriptor.html#functions-and-methods

Documentation:
>>> class D(object):
...     def f(self, x):
...         return x
...
>>> d = D()
>>> D.__dict__['f']  # Stored internally as a function
<function f at 0x00C45070>
>>> D.f              # Get from a class becomes an unbound method
<unbound method D.f>
>>> d.f              # Get from an instance becomes a bound method
<bound method D.f of <__main__.D object at 0x00B18C90>>

ipython3.5.3
In [1]: class D(object):
...: ... def f(self, x):
...: ... return x
...: ...

In [2]: d = D()

In [3]: D.__dict__['f'] # Stored internally as a function
Out[3]: <function __main__.D.f>

In [4]: D.f # Get from a class becomes an unbound method
Out[4]: <function __main__.D.f>

In [5]: d.f # Get from an instance becomes a bound method
Out[5]: <bound method D.f of <main.D object at 0x7f4e2e278c18>>

[JohannesLade]

And sorry for my lousy manners. Of course I appreciate all the hard work you do! It's just frustrating when you get confused by doc.

[rhettinger]

We have a sprint in early September and I'll fix it then.

[rhettinger]

New changeset 0d4497b by Raymond Hettinger in branch 'master':
bpo-23702: Update Descriptor-HOWTO to reflect the removal of unbound methods (bpo-3739)
0d4497b

[rhettinger]

New changeset 73c915a by Raymond Hettinger (Miss Islington (bot)) in branch '3.6':
[3.6] bpo-23702: Update Descriptor-HOWTO to reflect the removal of unbound methods (GH-3739) (bpo-3742)
73c915a