diff --git a/snippets/frequencies.md b/snippets/frequencies.md index 91dc18eda..f78fe75b5 100644 --- a/snippets/frequencies.md +++ b/snippets/frequencies.md @@ -5,12 +5,17 @@ tags: list,intermediate Returns a dictionary with the unique values of a list as keys and their frequencies as the values. -- Use `list.count()` to get the frequency of each unique element. -- Use `dict()` constructor to return a dictionary with the unique elements of the list as keys and their frequencies as the values. +- Use `collections.defaultdict()` to store the frequencies of each unique element. +- Use `dict()` to return a dictionary with the unique elements of the list as keys and their frequencies as the values. ```py +from collections import defaultdict + def frequencies(lst): - return dict((k, lst.count(k)) for k in lst) + freq = defaultdict(int) + for val in lst: + freq[val] += 1 + return dict(freq) ``` ```py