Python Programming with Jupyter and Anaconda

Functions in Python

Functions are a key concept in programming and allow us to create reusable and modular pieces of code. In Python, a function is defined using the def keyword followed by the function name and any parameters the function takes. For example, the following code defines a simple function that takes two arguments and returns their sum:


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

Functions can also have default values for their parameters, allowing us to call them without specifying all the arguments. For example, the following code defines a function that takes two arguments, with the second argument having a default value of 1:


def multiply_numbers(a, b=1):
    return a * b

To call a function, we simply use its name followed by any arguments that it takes. For example, to call the add_numbers function defined above, we would write:


result = add_numbers(3, 5)
print(result)

This would output 8.

In addition to returning values, functions can also modify the state of the program by changing the values of variables or data structures. For example, the following code defines a function that takes a list and adds an element to it:


def add_element_to_list(lst, element):
    lst.append(element)

To use this function, we would call it like this:


my_list = [1, 2, 3]
add_element_to_list(my_list, 4)
print(my_list)

This would output [1, 2, 3, 4].

Functions in Python

Functions in Python

Further Reading