Functions#

Introduction#

Functions are a fundamental component of Python programming, packaging code snippets in to reusable, efficient sections of code designed to perform a specific task. Functions can be called multiple times within a program, making code organization easier, and helping to avoid repeated code. Functions also make code easier to debug.

  • def defines a function.

  • return sends the function’s output back to the main program.

Usage:

def function_name(parameters):
    # Code to execute when the function is called
    return result  # Optional, used to return a value

Parameters

Description

function_name

A name you give to your function.

parameters

Optional. Variables that accept input values when the function is called, allowing data to be passed into the function.

result

Optional. Let the function send a result back to the caller. If a function does not include a return statement, it will return None by default.

Note: A function must always be defined before it is called.

Defining and Calling Functions#

Functions with No Parameters#

If a function does not require input, you can define it without parameters.

# Define a function to display a message
def greeting():
    robot.screen.print("Hello!")

# Call the function to display the message
greeting()

Functions with Parameters#

You can also add parameters to functions, which let you pass in information the function needs to work.

# Define a function with a parameter
def named_greeting(name):
    robot.screen.print("Hello, " + name + "!")
named_greeting("Stranger")

Functions with Default Arguments#

A default argument is a parameter that assumes a default value if a value is not provided in the function call for that argument.

# Define a function with a parameter and a default argument
def named_greeting(name = "Stranger"):
    robot.screen.print("Hello, " + name + "!")

# Use the default argument
named_greeting()
robot.screen.next_row()
# Change the parameter to a different name
named_greeting("AIM")

Return Values from Functions#

Functions can send data back to the caller using the return keyword. This allows you to capture and use the output in your program.

# Define a function that multiplies numbers by 2
def times_two(number):
    return number * 2

# Display the return value
robot.screen.print(times_two(2))
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