xray/xray — pull request #162 by ToddSmall (2014-06-15 23:10:29+00:00)
Title: Change np.isnan to pd.isnull in conventions.py to handle _FillValue = ''

At a number of spots in conventions.py, np.isnan was being used
to check possible fill values. However, np.isnan is not implemented
for string types. So, I've replaced np.isnan with pd.isnull.

Alas, I haven't been able to update the tests to cover _FillValue = '',
because doing so would involve significant changes throughout the
code base.