We've seen how lists hold collections of items, and how we can add (.append()) or remove (.remove()) items.

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But how can we easily find out exactly how many items are currently inside a list?

Every list has a length (or size), which is simply the count of items it contains.

A list like [10, 20, 30] has three items. An empty list [] has zero items.

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Does the length change when we append or remove items?

Python provides a built-in function called len() to get the length of a list. It's kind of like print() but only works on lists and returns the length.

You use it like this: len(your_list_variable). It takes the list as input inside the parentheses.

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What kind of value do you expect len() to give back? A string, a number, or something else?

The len() function returns an integer representing the number of items.

If colors = ["red", "green", "blue"], then would store the integer in the variable.