So far we have seen many different built-in Python functions. To give some examples: len, print, int, sum, max, min, str, list are all built-in Python functions that can be called and they do what they are supposed to. But these functions also have a source code very similar to the structure that will be outlined in this Python lesson.
These are nice and useful functions that are already defined in Python. They are very practical to use. You don’t need to do anything other than taking them and using them and they will do the job.
However, it’s also very useful to know how to define your own functions.
Defining a function is pretty simple and straightforward in Python but there are a few points you should keep in mind. We will explain all of those clearly here in this lesson.