Flatten nested dictionaries, compressing keys

Question

Suppose you have a dictionary like:

{\'a\': 1,
 \'c\': {\'a\': 2,
       \'b\': {\'x\': 5,
             \'y\' : 10}},
 \'d\': [1, 2, 3]}

Ho

Answer 1

Using generators:

def flat_dic_helper(prepand,d):
    if len(prepand) > 0:
        prepand = prepand + "_"
    for k in d:
        i=d[k]
        if type(i).__name__=='dict':
            r = flat_dic_helper(prepand+k,i)
            for j in r:
                yield j
        else:
            yield (prepand+k,i)

def flat_dic(d): return dict(flat_dic_helper("",d))

d={'a': 1, 'c': {'a': 2, 'b': {'x': 5, 'y' : 10}}, 'd': [1, 2, 3]}
print(flat_dic(d))


>> {'a': 1, 'c_a': 2, 'c_b_x': 5, 'd': [1, 2, 3], 'c_b_y': 10}