CODEWITHSUNDEEP
pythonpython-3.x
Prabu Raj
Prabu Raj

Reputation: 597

Iterating over collections.defaultdict(list)

import itertools
import collections

def get_pairs(some_list, limit):
    min = 2
    pair_dict = collections.defaultdict(list)

    for x in range(min, limit+1):
        pair_dict[x].append(list(itertools.combinations(some_list, x)))

    return pair_dict

z = get_pairs([1, 2, 3, 4], 4)
for key, value in z.items():
    print("Key: {}", "Value: {}".format(key, value))

Output:
Key: {} Value: 2
Key: {} Value: 3
Key: {} Value: 4

I was expecting key to come as 2, 3, 4 and value to be a list. Something like below

{
 2: [[(1, 2), (1, 3), (1, 4), (2, 3), (2, 4), (3, 4)]], 
 3: [[(1, 2, 3), (1, 2, 4), (1, 3, 4), (2, 3, 4)]], 
 4: [[(1, 2, 3, 4)]]
}

What is wrong with my code or am I missing something here?

Upvotes: 0

Views: 63

Answers (1)

user2390182
user2390182

Reputation: 73450

Your print statement is just messed up. Change it to:

print("Key: {}, Value: {}".format(key, value))

Your original

print("Key: {}", "Value: {}".format(key, value))

is printing the literal string "Key: {}" (without any formatting), followed by the formatted string "Value: {}".format(key, value) which uses the first argument key to fill its only placeholder.

It is easy to get fooled here with the placeholder "{}" looking like an empty dict and all =)

Upvotes: 2

Related Questions