[issue35331] Incorrect __module__ attribute for _struct.Struct and perhaps a few others

[Dan Snider]

Change by Dan Snider :


--
nosy:  -bup

___
Python tracker 

___
___
Python-bugs-list mailing list
Unsubscribe: 
https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com

[issue35331] Incorrect __module__ attribute for _struct.Struct and perhaps a few others

[Dan Snider]

Change by Dan Snider :


--
nosy: +bup

___
Python tracker 

___
___
Python-bugs-list mailing list
Unsubscribe: 
https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com

[issue35331] Incorrect __module__ attribute for _struct.Struct and perhaps a few others

[SilentGhost]

Change by SilentGhost :


--
nosy: +mark.dickinson, meador.inge, serhiy.storchaka
type:  -> behavior

___
Python tracker 

___
___
Python-bugs-list mailing list
Unsubscribe: 
https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com

[issue35331] Incorrect __module__ attribute for _struct.Struct and perhaps a few others

[Dan Snider]

New submission from Dan Snider :

_struct.Struct not defining a valid __module__ by prefixing its tp_name slot 
with "_struct" is inconsistent with every other extension type which is 
available in the corresponding module globals.

>From the documentation of the `tp_name` slot:

Pointer to a NUL-terminated string containing the name of the type. For types 
that are accessible as module globals, the string should be the full module 
name, followed by a dot, followed by the type name; for built-in types, it 
should be just the type name. If the module is a submodule of a package, the 
full package name is part of the full module name. For example, a type named T 
defined in module M in subpackage Q in package P should have the tp_name 
initializer "P.Q.M.T".

For dynamically allocated type objects, this should just be the type name, and 
the module name explicitly stored in the type dict as the value for key 
'__module__'.



I know that this is also a way to make something unpickleable, but that seems 
like a poor way to do it and since _struct.Struct was relatively alone in this, 
I figured it was an oversight.

At the end is the script I made to display all currently alive "builtins" 
classes that have been "PyType_Ready"ed. For brevity I further manually 
filtered out obvious cases where a specified module would be inappropriate. 

The main point is that I think the new contextvars classes, _struct.Struct, and 
the weakref classes are missing the "_struct", "_contextvars", and "_weakref" 
prefixes in their tp_name slots, respectively. Since _contextvars is one of the 
few extension modules using the multiphase initialization protocol, maybe it 
should go in their type dicts (although the prefix method still works) instead, 
although i think the docs were referring to heap allocated types.



if __name__=='__main__':
import sys, collections
subclassesof = type.__subclasses__
def get_types(*names):
r = {"__builtins__":{'__import__':__import__, 'globals':globals}}
for name in names:
exec(f'from {name} import __dict__ as d; globals().update(d)', r)
return dict.fromkeys(r[k] for k in r if isinstance(r[k],type)).keys()
def derivative_classes(cls):
a = b = r = {*subclassesof(cls)}
while b:
r, a, b, = r|b, b, set().union(*map(subclassesof, b))
return r | a
classes = derivative_classes(object)
singles = None, NotImplemented, ...
od = collections.OrderedDict()
odtypes = iter(od), od.keys(), od.items(), od.values()
bltns = {cls for cls in classes if cls.__module__=='builtins'}
bltns-= get_types('builtins', 'types', '_collections_abc')
bltns-= {*map(type, odtypes)} | {*map(type, singles)}
for cls in sorted(bltns, key=vars(type)['__name__'].__get__):
print(f'# {sys.getrefcount(cls):4} {cls.__name__}')

# all of these are in _contextvars.__dict__ but have their 
__module__=='builtins':
#   25 Context
#   15 ContextVar
#   12 Token

# from _struct
#   23 Struct # IS in _struct.__dict__
#   11 unpack_iterator # no tp_new so make sense to leave as-is

# These are here because it's a mystery how they were included in the results
# without importing _testcapi:
#   25 hamt
#8 hamt_array_node
#8 hamt_bitmap_node
#8 hamt_collision_node

# no idea what these are:
#   11 items
#   11 values
#   11 keys

# these are all in _weakref.__dict__
#   76 weakcallableproxy
#   76 weakproxy
#   32 weakref

--
messages: 330544
nosy: bup
priority: normal
severity: normal
status: open
title: Incorrect __module__ attribute for _struct.Struct and perhaps a few 
others
versions: Python 3.7, Python 3.8

___
Python tracker 

___
___
Python-bugs-list mailing list
Unsubscribe: 
https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com