I expected I could iterate over a DictProxy as I do over a regular dict.

>>> from multiprocessing import Manager
>>> m = Manager()
>>> d = m.dict()
>>> d
<DictProxy object, typeid 'dict' at 0x98a240c>
>>> for x in d:
...     print x
...
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<string>", line 2, in __getitem__
  File "/usr/lib/python2.6/multiprocessing/managers.py", line 740, in _callmethod
    raise convert_to_error(kind, result)
KeyError: 0
>>> d['a'] = 1
>>> for x in d:
...     print x
...
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<string>", line 2, in __getitem__
  File "/usr/lib/python2.6/multiprocessing/managers.py", line 740, in _callmethod
    raise convert_to_error(kind, result)
KeyError: 0

> I expected I could iterate over a DictProxy as I do over a
> regular dict.

DictProxy doesn't support iterkeys(), itervalues(), or iteritems() either.
So while

    iter(d)

could do
     iter(d.keys())

behind the scenes, it would mask the fact that this would not return
an *iterator* over the keys, but send a potentially long list of keys back to the client.