Sum value in dictionary key python : I have a python dictionary like the one below:


    {'Jason': {'A': 200, 'B': 'NaN', 'C': 34, 'D': 'NaN', 'E': True},
     'John': {'A': 250, 'B': '34', 'C':98, 'D': 59, 'E': False},
     'Steve': {'A': 230, 'B': '45', 'C':'NaN', 'D': 67, 'E': False},
     'Louis': {'A': 220, 'B': '37', 'C':'NaN', 'D': 'Nan', 'E': True},
     ....
    }

I want to count the number of `'NaN'` in each value, and return that count with the number of `'NaN'` that have the value `'E': True`. 

So I would like to create a dictionary like this:

    {'A': {'NaN': 0, 'E': 0},
     'B': {'NaN': 1, 'E': 1},
     'C': {'NaN': 2, 'E': 1},
     'D': {'NaN': 2, 'E': 2}}
 


Thanks for the help!