Python and the Building Blocks of Programming

• You will learn the anatomy of a program and what a typical Python program consists of.
• Introduce variables, data structures and functions as basic building blocks of a program
• Introduce classes and objects as advanced building blocks of a program.

Each building blocks can be used in different ways, and not all of them are required in a single program. Using these blocks, we can gradually construct our program in different ways until we achieve the desired functionality.

By the end of this post, you will have a first introduction of what constitutes a basic Python program by understanding what variables are.

In the next post you will be able to create interactive dialogues with users and store information in variables and data structures.

Data handling is a fundamental of any program so it’s important to understand this early on.

Every program is made up of one or more building blocks. We will explore all of them in a series of posts in this blog.

• Variables
• Data Structures
• Functions
• Classes

Each building block serves a specific purpose, categorized into storing information (data) or processing it.

Examples of processing information could be:

• Calculating VAT given a price.
• Determining loan costs based on loan amount and interest rate.
• Extracting parts of speech (e.g., verbs, nouns) from a long text or simply calculating the text’s length.
• Calculating age based on a birthdate.

Examples of holding (storing) information could be:

• Storing personal details throughout a program
• Storing account balance
• Storing textual information about a book or news site

Here’s an example of some building blocks in a program, feel free to try it out in your Python environment.

Have you not installed Python yet? Check out the simple guide we have

How To Install Python On Your Computer

For the examples in this post, it’s sufficient to write them in IDLE. However, if you are already familiar or prefer VSCode, PyCharm or another editor, feel free to do so.

Each file you create are called a module. You may encounter both when you read online resources.

To create a new file in IDLE, go to File -> New File. Name the new file building_blocks_ex1.py.

You will see an empty window where you can write your code. Paste the following code and then go to Run -> Run Module.

name = 'Karl'
direction = 'North'
cost = 200
print(name)
print(direction)
print(cost)

The example above demonstrates a short program showcasing variables, assignment, and output. The left hand side is the variable name and the right hand side is the value assigned to that variable.

A variable is a container to store data in your program.

Python has many built-in functions that we will use, one of them is the useful print(). That will output to your window the result of each variable we created: name, direction and cost.

Practice writing your own variables. Notice the following

• What happens if you change single quote to double quotes?
• Can you change cost to something other than a number? Like a name?
• Create a new variable and name it, e.g. salary, age, points – use your imagination!
• Print the newly created variable(s).
• What happen if you combine the print like so print(name, direction, cost)?

This was a short introduction to variables and already in the next post we will build on this to interact with a user.