Chars-Counter Python

Question

I am looking for a solution:

Input is a string like s = "Hello World!"
The function should return a dictionary like:
{'e': 1, 'H': 1, 'r': 1, 'o': 2, 'd': 1, ' ': 1, 'l': 3, 'W': 1}

i just got an inefficient solution with get:

def char_count_dict(count_string):
     letter_dict = {}
     for letter in count_string:
         letter_dict[letter] = letter_dict.get(letter, 0)+1
     return letter_dict

Why do you thing your implmentation is _inefficient_? You'll obviously get an answers with `.setdefault`, `defaultdict` and `collections.Counter` but effectively they all do same thing as your `.get` under the hood. — Łukasz Rogalski, Apr 14 '20 at 11:16
So maybe add some logic to check the dtype of the indivudual characters, and then build a Counter — yatu, Apr 14 '20 at 11:16
"inefficient solution".the time complexity is O(n).I think it is good. — jizhihaoSAMA, Apr 14 '20 at 11:16
It should contain the str.count-function and a dictionary comprehension. — John Hopesand, Apr 15 '20 at 08:14

score 0 · Accepted Answer · answered Apr 14 '20 at 11:15

0

You can use high-performance container datatypes like collections.Counter https://docs.python.org/2/library/collections.html#collections.Counter

from collections import Counter

def char_count_dict(count_string):
    return dict(Counter(count_string))

answered Apr 14 '20 at 11:15

Maciej M

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17

It should contain the str.count-function and a dictionary comprehension. – John Hopesand Apr 15 '20 at 08:14

Chars-Counter Python

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