[Python-Dev] class dict of subtyped types (original) (raw)

Guido van Rossum guido@python.org
Mon, 29 Oct 2001 15:04:12 -0500

C:>python Python 2.2b1+ (#25, Oct 19 2001, 14:30:05) [MSC 32 bit (Intel)] on win32 Type "help", "copyright", "credits" or "license" for more information. >>> class INT(int): pass ... >>> INT.dict <dict-proxy object at 0x00769680> >>> INT.dict.update Traceback (most recent call last): File "", line 1, in ? AttributeError: 'dict-proxy' object has no attribute 'update' >>> dir(INT.dict) ['class', 'contains', 'delattr', 'getattribute', 'getitem', 'hash' , 'init', 'iter', 'len', 'new', 'reduce', 'repr', 'setattr', ' str', 'copy', 'get', 'haskey', 'items', 'keys', 'values'] >>>

Other dict attributes are missing as well in the dict-proxy. Is this intentional?

The dict-proxy type is intended to provide a read-only proxy, so the dict-proxy is consciously lacking the update, clear, popitem and setdefault methods. It also seems to be missing the comparison operations; that's an oversight.

--Guido van Rossum (home page: http://www.python.org/~guido/)