[Python-bugs-list] [ python-Bugs-746304 ] TypeError raised when deepcopying built-in functions

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Bugs item #746304, was opened at 2003-05-30 22:59
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Category: Python Library
Group: Python 2.3
Status: Open
Resolution: None
Priority: 5
Submitted By: Oktay Safak (oktaysafak)
Assigned to: Nobody/Anonymous (nobody)
Summary: TypeError raised when deepcopying built-in functions

Initial Comment:
>>> import copy
>>> copy.deepcopy(max)

Traceback (most recent call last):
  File "<pyshell#2>", line 1, in ?
    copy.deepcopy(max)
  File "C:\PYTHON23\lib\copy.py", line 205, in deepcopy
    y = _reconstruct(x, rv, 1, memo)
  File "C:\PYTHON23\lib\copy.py", line 336, in _reconstruct
    y = callable(*args)
  File "C:\PYTHON23\Lib\copy_reg.py", line 84, in __newobj__
    return cls.__new__(cls, *args)
TypeError: object.__new__(builtin_function_or_method) is not 
safe, use builtin_function_or_method.__new__()

Steven Taschuk's guess is that all things pickleable should be 
copyable since copy uses the same protocol as pickle. (He is 
not sure though) He demonstrates this idea with the following 
example:

>>> import pickle
>>> pickle.loads(pickle.dumps(max))
<built-in function max>

which succeeds unlike the first example.

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