Merge two dictionaries of dictionaries
My question is similar to this one, but the answers don't produce the right result (for me?).
Take these dictionaries:
a = {'a': {'a': 1}}
b = {'a': {'b': 2}}
I want to produce:
c = {'a': {'a': 1, 'b': 2}}
Using the answers from the quoted question, these all produce:
c = a.copy()
c.update(b)
>>
c == {'a': {'b': 2}
Consider that a and b might be more complex than this, for example:
a = {'a': {'aa': {'aaa': 1}, 'bb': {'bbb': 2}}}
b = {'a': {'bb': {'aaa': 1}, 'bb': {'bbb': 2}}}