Nested dictionary comprehension python

Question

I\'m having trouble understanding nested dictionary comprehensions in Python 3. The result I\'m getting from the example below outputs the correct structure without error,

Answer 1

Adding some line-breaks and indentation:

data = {
    outer_k: {inner_k: myfunc(inner_v)} 
    for outer_k, outer_v in outer_dict.items()
    for inner_k, inner_v in outer_v.items()
}

... makes it obvious that you actually have a single, "2-dimensional" dict comprehension. What you actually want is probably:

data = {
    outer_k: {
        inner_k: myfunc(inner_v)
        for inner_k, inner_v in outer_v.items()
    } 
    for outer_k, outer_v in outer_dict.items()
}

(which is exactly what Blender suggested in his answer, with added whitespace).