Python 101

Python Functions

In Python, a function is a block of code that performs a specific task and can be reused multiple times in a program. Functions are an essential part of Python, and they can help you to organize and structure your code, making it easier to understand and maintain.

To create a function in Python, you use the def keyword, followed by the function name and a pair of parentheses. You can also specify parameters inside the parentheses, which are variables that will be passed to the function when it is called. For example:

def greet(name):
    print("Hello, " + name)

This function, called greet, takes one parameter, name, and prints a greeting using that parameter.

To call a function in Python, you simply use its name, followed by a pair of parentheses and any required arguments. For example:

greet("John")

This will output “Hello, John”.

Functions can also return a value using the return keyword. For example:

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

result = add(2, 3)
print(result)

This function, called add, takes two parameters, a and b, and returns the sum of those two values. When the function is called, it returns the value 5, which is then stored in the variable result.

You can define as many functions as you need in your Python program, and you can call a function from within another function. Functions can also be defined inside other functions, which are called nested functions.

Functions are a powerful and flexible tool in Python, and they are an essential part of writing modular and reusable code.