datetime comparison

[djkirkham]

When a netcdftime datetime object is unable to be compared to another object, the __richcmp__ method raises a TypeError. In previous versions of the module the method would return NotImplemented, causing the appropriate method on the other object to be called and allowing classes to be written which could be compared against netcdftime datetime objects. With the TypeError behaviour this is no longer the case.

Can the previous behaviour be restored?

[jswhit]

netcdftime is being split out into a separate package. I created a copy of this issue at Unidata/cftime#11.