Translations:Introduction to Python/181/en

The command defines a new function, you give it a name, and inside the parenthesis you define the arguments that the function will use. Arguments are data that will be passed to the function. For example, look at the command. If you just write, Python will tell you it needs an argument. Which is obvious: you want to know the length of something. If you write then  is the argument that you pass to the  function. And the function is defined in such a way that it knows what to do with this argument. We have done the same thing with our function.