如果嵌套的字典键名与另一个字典键名匹配，则重命名

Question

Say I have a nested dictionary

dict1 = {'London': {'car_toyota': 288, 'car_audi': 64, 'car_bmw': 426}, 'Paris': {'car_toyota': 48, 'car_audi': 96}, 'New York': {'car_bmw': 48}

And have normal dictionary

dict2 = {'car_toyota': 'Toyota', 'car_audi': 'Audi', 'car_bmw': 'BMW'}

I want to rename the keys in dict1 with the value of the corresponding key in dict2, so it would look like

{'London': {'Toyota': 288, 'Audi': 64, 'BMW': 426}, 'Paris': {'Toyota': 48, 'Audi': 96}, 'New York': {'BMW': 48}

I'm getting stuck in messy nested loops that don't seem to give what I want

for i, j in dict1.iteritems():
    for k, v in j.items():
        for a, b in dict2.items():
            if k == a:
                j[k] == j.pop(a)

What would be the best way to do this?

Answer 1

You can use nested dictionary comprehension:

dict1 = {'London': {'car_toyota': 288, 'car_audi': 64, 'car_bmw': 426}, 'Paris': {'car_toyota': 48, 'car_audi': 96}, 'New York': {'car_bmw': 48}}
dict2 = {'car_toyota': 'Toyota', 'car_audi': 'Audi', 'car_bmw': 'BMW'}
final_d = {a:{dict2[c]:d for c, d in b.items()} for a, b in dict1.items()}

Output:

{'Paris': {'Toyota': 48, 'Audi': 96}, 'New York': {'BMW': 48}, 'London': {'Toyota': 288, 'BMW': 426, 'Audi': 64}}