What does the len() function do in Python?

Hello Ernest, really nice question.

In Python, len() is a built-in function that tells you how many items are in something.

You give it an object like a list, string, tuple, etc., and it returns an integer:

languages = ['Python', 'JavaScript', 'C++']
print(len(languages))   # 3

Here, len(languages) is 3 because there are three items in the list.

It works the same way with strings:

word = "Hello"
print(len(word))   # 5

And with an empty list:

items = []
print(len(items))  # 0

So the simple way to remember it:

len(x) gives you “how many things are inside x”.

If you have further questions, I'm here to help.