Python Functions

Python functions

Created By: chatGPT

Functions in Python are defined using the def keyword. A function is a block of code that only runs when it is called. You can pass data, known as parameters, into a function and it can return data as a result.

def greet(name):
    return f'Hello, {name}!'

In the example above, we defined a function called greet that takes one parameter, name. It uses an f-string to return a greeting message.

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

Functions can have default parameter values. If no value is provided for a parameter, the default value will be used.

def greet(name='Guest'):
    return f'Hello, {name}!'

Now, if we call greet() without any argument, it will use the default value 'Guest'.

print(greet())  # Output: Hello, Guest!

You can also define functions that can take an arbitrary number of arguments using *args. This allows you to pass a variable number of arguments to the function.

def add_numbers(*args):
    return sum(args)

In this example, add_numbers can take any number of arguments and return their sum.

print(add_numbers(1, 2, 3, 4))  # Output: 10

Similarly, to pass key-value pairs, you can use **kwargs, which allows you to handle named arguments.

def display_info(**kwargs):
    for key, value in kwargs.items():
        print(f'{key}: {value}')

This function prints each key-value pair passed to it. You can call display_info with any number of named arguments.

display_info(name='Alice', age=30, city='New York')

Remember, a return statement is used to exit a function and return a value. If a function does not return a value, Python will return None by default.

def square(x):
    return x ** 2

You can use this function to calculate the square of a number.

print(square(4))  # Output: 16