Fastest way to count number of occurrences in a Python list

Question

I have a Python list and I want to know what\'s the quickest way to count the number of occurrences of the item, \'1\' in this list. In my actual case, the item

Answer 1

You can use pandas, by transforming the list to a pd.Series then simply use .value_counts()

import pandas as pd
a = ['1', '1', '1', '1', '1', '1', '2', '2', '2', '2', '7', '7', '7', '10', '10']
a_cnts = pd.Series(a).value_counts().to_dict()

Input  >> a_cnts["1"], a_cnts["10"]
Output >> (6, 2)