building a dict

[vsoler]

Say that "m" is a tuple of 2-tuples

m=(('as',3), ('ab',5), (None, 1), ('as',None), ('as',6))

and I need to build a "d" dict where each key has an associated list
whose first element is the count, and the second is the sum. If a 2-
tuple contains a None value, it should be discarded.

The expected result is:
d={'as':[2, 9], 'ab': [1,5]}

How should I proceed? So far I have been unsuccessful. I have tried
with a "for" loop.

Thank you for your help