Python for Basic Data Analysis

Functions are a way of writing code whereby you group together a set of "tasks". Therefore, instead of writing tasks individually, multiple times, you simply use the Function that houses the set of tasks. 

This means if you have a repetitive task, you do not have to write the code over and over. Just write the code into a function and use the function to do the task.

Functions will be building blocks for constructing complex codes. 

Structure of a function

Functions start with a def, followed by a function name and parenthesis, the docstring (optional), the function statements (i.e. codes) and ending with either return, pass, or nothing at all. Watch the accompanying video for a more detailed explanation. 

Python functions usually looks something like this:

Syntax

def functionname(arguments):

 """This is the docstring that explains what this function is supposed to do"""
 
 function statements

 return

Calling a function

To use the function we simply call its name by writing functionname()

Example

In this example, my function name is hello.
Note that this function does not have a return statement, otherwise known as a void function.

Here is another example of a void function. The function rounds any decimal number that a user inputs to 3 decimal places. 

From 1.41 to 4.58