How to filter a nested dictionary (pythonic way) for a specific value using map or filter instead of list comprehensions?

Question

I\'ve a nested dictionary.

>>> foo = {\'m\': {\'a\': 10}, \'n\': {\'a\': 20}}
>>> 

I\'d like to filter specific values, b

Answer 1

A list comprehension can do this beautifully.

>>> foo = {'m': {'a': 10}, 'n': {'a': 20}}
>>> [v for v in foo.values() if 10 in v.values()]
[{'a': 10}]

You don't need the for loop or the list comprehension if you are matching against a known key in the dictionary.

In [15]: if 10 in foo['m'].values():
    ...:     result = [foo['m']]
    ...:     

In [16]: result
Out[16]: [{'a': 10}]