How can I count the occurrences of a list item?

Question

Given an item, how can I count its occurrences in a list in Python?

Answer 1

If you only want one item's count, use the count method:

>>> [1, 2, 3, 4, 1, 4, 1].count(1) 3 

Important Note regarding count performance

Don't use this if you want to count multiple items.

Calling count in a loop requires a separate pass over the list for every count call, which can be catastrophic for performance.

If you want to count all items, or even just multiple items, use Counter, as explained in the other answers.