Why Python3.2 can't deepcopy(globals())?

Question

I have run these codes in python 3.2.2 IDLE:

from copy import deepcopy
deepcopy(globals())

And i get the error message:

Traceback (most recent call last):
  File "H:\　  　 　\python\copy deepcopy.py", line 27, in <module>
    deepcopy(globals())
  File "D:\Program Files\Python32\lib\copy.py", line 147, in deepcopy
    y = copier(x, memo)
  File "D:\Program Files\Python32\lib\copy.py", line 236, in _deepcopy_dict
    y[deepcopy(key, memo)] = deepcopy(value, memo)
  File "D:\Program Files\Python32\lib\copy.py", line 174, in deepcopy
    y = _reconstruct(x, rv, 1, memo)
  File "D:\Program Files\Python32\lib\copy.py", line 290, in _reconstruct
    state = deepcopy(state, memo)
  File "D:\Program Files\Python32\lib\copy.py", line 147, in deepcopy
    y = copier(x, memo)
  File "D:\Program Files\Python32\lib\copy.py", line 236, in _deepcopy_dict
    y[deepcopy(key, memo)] = deepcopy(value, memo)
  File "D:\Program Files\Python32\lib\copy.py", line 174, in deepcopy
    y = _reconstruct(x, rv, 1, memo)
  File "D:\Program Files\Python32\lib\copy.py", line 285, in _reconstruct
    y = callable(*args)
  File "D:\Program Files\Python32\lib\copyreg.py", line 88, in __newobj__
    return cls.__new__(cls, *args)
TypeError: object.__new__(NotImplementedType) is not safe, use NotImplementedType.__new__()

So I don't know why we can't do deepcopy() to globals()?

Because that the deepcopy() change the globals dict when it exec?

Answer 1

不，这不是因为deepcopy执行时会更改globals dict，但正如异常所示，它在处理过程中遇到了特殊的NotImplemented 内置常量 ，即NotImplementedType类型的元素，无法实例化并进行复制。