In this lab, we introduced several major important topics in Python. Let’s quickly review them.

Python Functions

A function in Python is a piece of code that is given a name, which can then be run by calling it elsewhere in the program.

To create a function, we use the following structure:

def function_name(parameter1, parameter2):
    <block of statements>

1. Function names follow the same rules as variable names.
2. Functions may require 0 or more parameters, placed in parentheses after the function name. Multiple parameters are separated by commas.
3. When called, a function will run the lines of code indented beneath the function definition.

To call a function, we use the following structure:

function_name(argument1, argument2)

1. A function call is the function name, followed by parentheses ().
2. Inside of the parentheses, a matching argument must be included for each parameter required by the function. Multiple arguments are separated by commas.
3. Each argument may be an expression that evaluates to a value.
4. The values of each argument are copied into the function. When the function ends, the original arguments are unchanged.

Returning Data from Functions

• return expression will return the value of expression to where the function was called from.
• Function calls can be used in assignment statements to store return values, or as part of other expressions.