How can you iterate through a tuple (str), then return a dictionary containing the keys (from the tuple) and the index of the keys as the values?

How can you iterate through a tuple (str), then return a dictionary containing the keys (from the tuple) and the index of the keys as the values?

Input:

tup = ('A', 'A', 'B', 'B', 'A')

Return a dictionary that looks like this:

{'A': [0, 1, 4], 'B': [2, 3]}

>Solution :

Use a defaultdict:

tup = ('A', 'A', 'B', 'B', 'A')

from collections import defaultdict

d = defaultdict(list)
for i,k in enumerate(tup):
    d[k].append(i)
    
dict(d)

or with a classical dictionary:

d = {}
for i,k in enumerate(tup):
    if k in d:
        d[k].append(i)
    else:
        d[k] = [i]

output: {'A': [0, 1, 4], 'B': [2, 3]}