[pypy-issue] Issue #2252: collections.defaultdict has the wrong modulel (pypy/pypy)

[David MacIver]

New issue 2252: collections.defaultdict has the wrong modulel
https://bitbucket.org/pypy/pypy/issues/2252/collectionsdefaultdict-has-the-wrong

David MacIver:

The following passes on CPython 2.7.10 and fails on pypy-4.0.1

```python
from collections import defaultdict

assert defaultdict.__module__ == 'collections', defaultdict.__module__
```

This happens because defaultdict reports its module as '_collections' rather than 'collections'

I discovered this because it breaks IPython's pretty printing for defaultdicts because of the way it handles lookup.

Note: Counter correctly reports it smodule as 'collections' rather than '_collections'