CODEWITHSUNDEEP
pythondictionarydictionary-comprehension
Sanglang
Sanglang

Reputation: 81

count number of times a value occurs in a dictionary of lists, where keys are number of occurrences

I would like to know how many times each item in a list occurs, in a dictionary of lists. The keys are the number of occurrences per value, and the value can occur across multiple keys.

So,

{1: ['intel', 'mail', 'com'], 50: ['yahoo', 'com'], 900: ['google', 'mail', 'com'], 5: ['wiki', 'org']}

Would contain

and so on.

I'm trying to solve this problem, and I decided to make everything into a dictionary:

        cpdomains = ["900 google.mail.com", "50 yahoo.com", "1 intel.mail.com", "5 wiki.org"]
        
        split_number = [x.split(' ') for x in cpdomains]
        
        domain = {int(x[0]): x[1].split('.') for x in split_number}

gave me that dictionary.

Upvotes: 0

Views: 129

Answers (1)

Alain T.
Alain T.

Reputation: 42143

You can use the Counter object (from collection) with reduce (from functools) to accumulate all word counts into a big Counter dictionary with the totals:

from collections import Counter
from functools import reduce


countWords = {1: ['intel', 'mail', 'com'], 
             50: ['yahoo', 'com'], 
            900: ['google', 'mail', 'com'], 
              5: ['wiki', 'org']}

toCounter  = lambda cw: Counter({w:cw[0] for w in cw[1]})
wordCounts = reduce(Counter.__add__, map(toCounter,countWords.items()) )

print(wordCounts)

Counter({'com': 951, 'mail': 901, 'google': 900, 
       'yahoo': 50,  'wiki': 5,      'org': 5, 'intel': 1})

Upvotes: 1

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