Step 1: Define

Before you do anything else, you have to define your function.

The def keyword tells Python that you are defining a function.

For instance, def func_name(argument1): tells Python that you are making a function with name func_name and argument(s) argument1.

def square(number):
	# to print the square of the number, use number**2
	print(number**2)

There is another use of function called return.

def square(number):
	# instead, we return the number squared
	return number**2

The keyword return tells Python that this is the value this function gives.

The second one is just like a function in maths, except the square might be just f instead:

It is equivalent to $f(x)=x^2$.

Multiple arguments are seperated by a comma, the () must be included even if there are no parameters.

Step 2: Call

You call a function the same way you define it.

Take the square code:

You used square(number), so when you call it, use square(5) to get the square of a number (in this case, 5).

square(37)

Done!!!

Now you are done!!!