Summary

Make DType objects, their corresponding types, and their string names all compare unequal.

Historical issue

For some reason, dtype objects and the numpy types they are based off of compare equal. They don't hash equal of course, which goes against Python's docs that say

The only required property is that objects which compare equal have the same hash value…

Can we make them compare unequal? Is there any reason for them to compare equal?

In [6]: np.dtype(np.float) == np.float
Out[6]: True