Creating a function
Functions are used to group useful pieces of code together so that you can give them a name and easily use them whenever you want.
Use the keyword def to define a function
Give the function a name
Add any parameters between the brackets
for example ...
This function doesn't have any parameters so we just use round brackets with nothing inbetween - they're still needed though.
Using or 'calling' a function
Using a parameter with a function
Calling a function with a parameter
The program on the left shows how you can call the same function with a different parameter to make the function do different things.
You should always call a function with exactly the number of parameters set out in the def statement (the definition)