Modify value in nested dictionary

Question

This is my code

def increase_by_one(d):
    for key, value in d.items():
        if d[value] == type(int): ## There is an error here
            d[value] = d[value] + 1
        else:
            d[key] += 1
    return d

I am not sure what is wrong. But I am sure it's if d[value] == type(int) that is wrong. How can I change it ?

Input

increase_by_one({'a':{'b':{'c':10}}})

Output

{'a':{'b':{'c':11}}}

Input

increase_by_one({'1':2.7, '11':16, '111':{'a':5, 't':8}})

Output

{'1':3.7, '11':17, '111':{'a':6, 't':9}}

Answer 1

From your previous post , here's my answer fixed to provide the solution you want:

def increase_by_one(d):
    for key in d:
        try:
            d[key] += 1
        except TypeError:
            d[key] = increase_by_one(d[key])
    return d

Every time you try to add 1 to a dictionary, a TypeError is raised. Since you know you're dealing with nested dictionaries, you call your function again. This is called recursion.

>>> increase_by_one({'a':{'b':{'c':10}}})
{'a': {'b': {'c': 11}}}

>>> increase_by_one({'1':2.7, '11':16, '111':{'a':5, 't':8}})
{'1': 3.7, '11': 17, '111': {'a': 6, 't': 9}}

Answer 2

First of all use isinstance() and iteritems()

for key, value in d.iteritems():

    if isinstance(value,int):
        ...

But as you are dealing with nested dicts this won't do. Either use recursion or if you know the depth of your dict, first do a check like isinstance(value,dict)

Answer 3

You are indexing by value, but you should be using the key and no need to get the value from the dictionary since you are already using items() :

def increase_by_one(d):
    for key, value in d.items():
        if type(value) == int:
            d[key] = value + 1
        else:
            increase_by_one(value) # if you want recursion
    return d