Python Functions

Functions in Python are blocks of code that are designed to do one specific job. They allow you to break your code into smaller, reusable pieces, which can make your code more organized, readable, and easier to maintain. In this lesson, we will cover the basics of functions and how to use them.

Defining a Function

You can define a function in Python using the def keyword, followed by the function name and a set of parentheses. For example:

def greet():
    print('Hello, world!')

Calling a Function

To call a function, simply write its name followed by a set of parentheses. For example:

greet()  # Output: 'Hello, world!'

Parameters

You can pass information to a function by using parameters. Parameters are specified inside the parentheses when defining the function. For example:

def greet(name):
    print('Hello, ' + name + '!')

greet('Alice')  # Output: 'Hello, Alice!'

Return Values

Functions can also return a value using the return keyword. For example, a function that adds two numbers and returns the result:

def add(a, b):
    return a + b

result = add(3, 5)
print(result)  # Output: 8

Conclusion

Functions are an essential concept in Python programming, allowing you to write modular and reusable code. By understanding how to define, call, and use functions with parameters and return values, you can create more powerful and flexible Python programs.