Course Content

Python Functions Tutorial

1. What is Function in Python?

What Is Function?Challenge: Building functions Arguments Return Value Function Body Built-in Functions

2. Positional and Optional Arguments

Positional Arguments Challenge: Positional Arguments Optional Arguments Challenge: Optional Arguments

3. Arbitrary Arguments

Arbitrary Arguments Arbitrary Keyword Arguments Combination of Positional and Optional Arguments

4. Function Return Value Specification

Single Return Value Multiple Return Values None Return Value Generator Functions Challenge: Traffic lights

5. Recursion and Lambda Functions

Recursion Challenge: Pyramid Lambda Functions Immediately Invoked Lambda Expression Writing Effective and Maintainable Functions

Function Body

The function body refers to the block of code contained within a function. It is part of the function definition where you write the instructions or statements that define the function's behavior.

We have already used mathematical formulas and the print() function as the body in the previous chapters. However, the function body can be more complex, containing loops, if-else statements, keywords, or other code to realize necessary logic.

We have to use one indentation to define the function body. Indentation in Python refers to the spacing of code lines to define the structure and hierarchy of the code.
In the context of functions, indentation defines the function's body, including all the statements executed when the function is called.

Example: Cat's Health Level

Write a function that determines a cat's health level based on the amount of calories it consumes daily. Consider the following conditions:

If the cat consumes less than 200 calories per day, the health level is "low";
If the cat consumes between 200 and 400 calories per day, the health level is "average";
If the cat consumes more than 400 calories per day, the health level is "high".


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def health_level_for_cat(calories_per_day):
	# Use one indentation to create function body
    if calories_per_day < 200:
        health_level = 'Low'
    elif 200 <= calories_per_day <= 400:
        health_level = 'Average'
    else:
        health_level = 'High'

    message = f"The cat's health level based on calorie intake is {health_level}."
    return message

# Example usage of the function
daily_calories_for_cat = 300
result = health_level_for_cat(daily_calories_for_cat)
print(result)

The function's body starts with the definition of the function, and inside the function, an if-else statement is used to determine the cat's health level based on the daily calorie intake. Following the conditional statement, the function forms a message based on the health level and returns it as the result of the function.

In this specific case, depending on the amount of calories, the function determines the cat's health level and generates a message accordingly, which is then printed as the output of the function.

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Section 1. Chapter 5