python – How do I count occurrence of unique values inside a list

python – How do I count occurrence of unique values inside a list

In addition, use collections.Counter to refactor your code:

from collections import Counter

words = [a, b, c, a]

Counter(words).keys() # equals to list(set(words))
Counter(words).values() # counts the elements frequency

Output:

[a, c, b]
[2, 1, 1]

You can use a set to remove duplicates, and then the len function to count the elements in the set:

len(set(new_words))

python – How do I count occurrence of unique values inside a list

values, counts = np.unique(words, return_counts=True)

More Detail

import numpy as np

words = [b, a, a, c, c, c]
values, counts = np.unique(words, return_counts=True)

The function numpy.unique returns sorted unique elements of the input list together with their counts:

[a, b, c]
[2, 1, 3]