Python's Functions

Why use a Function?

Functions are a convenient way to group our code into reusable blocks. A function contains a sequence of steps that can be performed repeatedly throughout a program without having to repeat the process of writing the same code again

Function Key Components

There are some key components we want to note here:

· The def keyword indicates the beginning of a function (also known as a function header). The function header is followed by a name in snake_case format that describes the task the function performs. It’s best practice to give your functions a descriptive yet concise name.

· Following the function name is a pair of parenthesis ( ) that can hold input values known as arguments.

· A colon: to mark the end of the function header.

· Lastly, we have one or more valid python statements that make up the function body.

Function Types

There are three types of functions in Python:

1. Built-in functions:

such as help() to ask for help, min() to get the minimum value, print() to print an object to the terminal.

2. User-Defined Functions (UDFs):

which are functions that users create to help them out

3. Anonymous Functions / Lambda Function:

which are also called lambda functions because they are not declared with the standard (def) keyword.

Calling a Function

The process of executing the code inside the body of a function is known as calling it (This is also known as “executing a function”). To call a function in Python, type out its name followed by parentheses ( ).

Function Arguments

arguments are the things that are given to any function or method call, while the function or method code refers to the arguments by their parameter names.

1. Positional arguments:

arguments that can be called by their position in the function definition.

1. Keyword arguments:

arguments that can be called by their name.

1. Default arguments:

arguments that are given default values.

4. Variable Length Positional Arguments (*args):

arguments that allow the function to take an unlimited number of positional arguments

5. Variable Length Keyword Arguments (**kwargs):

arguments that allow the function to take an unlimited number of keyword arguments