Is len() a method or a function?

So the wording is tricky so I will try my best to explain. Let me know if you want me to clarify further.

The short answer: it is both. Len() is a method, and therefore also a function.

Generally speaking, a method is a function that is usually associated with a class or object. So it would be true to say that all methods are functions but not all functions are methods, since you can create a function outside of a class or object that will not be associated with either.

In this particular case, the len() method is actually associated with Python itself. Python comes out of the box with some ready to go methods to help developers, such as str(), int(), etc. This makes it a Python method.

Here is a simple example of two functions, one associated with a class and another that is not:

class SomeClass:

    def some_function(self):
         pass

def some_function():
    pass

The first belongs to the SomeClass class so it is a method of that class. The second belongs to nothing so it is just a function.

Hope that helps!!!