C:\Users\Jakob>python -c "import copy; copy.copy(iter([1,2,3]))"
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "T:\languages\Python27\lib\copy.py", line 96, in copy
    return _reconstruct(x, rv, 0)
  File "T:\languages\Python27\lib\copy.py", line 329, in _reconstruct
    y = callable(*args)
  File "T:\languages\Python27\lib\copy_reg.py", line 93, in __newobj__
    return cls.__new__(cls, *args)
TypeError: object.__new__(listiterator) is not safe, use listiterator.__new__()

C:\Users\Jakob>python3 -c "import copy; copy.copy(iter([1,2,3]))"
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "T:\languages\Python32\lib\copy.py", line 97, in copy
    return _reconstruct(x, rv, 0)
  File "T:\languages\Python32\lib\copy.py", line 285, in _reconstruct
    y = callable(*args)
  File "T:\languages\Python32\lib\copyreg.py", line 88, in __newobj__
    return cls.__new__(cls, *args)
TypeError: object.__new__(list_iterator) is not safe, use list_iterator.__new__()

Pure python traceback. Just for clarity.