What is Python, really?

Python in one sentence

Python is a way of writing instructions for your computer in language that looks a lot like English. That's it. Once you write the instructions down in a file, you tell the computer to run the file, and the computer does what you said.

Here's a complete, working piece of Python:

print("Hello, Excel friend!")

You can probably guess what that does before you've ever written a line of code: it prints the words "Hello, Excel friend!" to the screen. That readability is the whole point of Python.

Where Python sits in the world

Python is one of the two or three most-used programming languages on the planet. NASA uses it. Netflix uses it. Your bank uses it. The data science team at virtually every company uses it. And starting in 2023, Microsoft Excel itself uses it — there's a Python interpreter built right into the spreadsheet now, accessed through a formula called =PY().

That last bit is the reason this course exists. The world's most popular spreadsheet now ships with the world's most popular data language built in. If you've spent years living inside Excel, you've just been handed a superpower.

What is Python good at?

Roughly the kind of work an Excel power-user already does — and then a lot more:

• Working with data. Cleaning it, reshaping it, summarising it, joining tables, building charts. Python's pandas library is what most of the world's data analysts use.
• Automating repetitive computer tasks. Renaming a thousand files, merging a hundred spreadsheets, sending a personalised email to each row of a list.
• Getting data from places. Web pages, APIs, PDFs, databases, emails — Python can pull data from almost anything.
• Calculation and math. Anything from a budget reconciliation to a machine-learning model.
• Building things. Websites, mobile apps, games, scientific simulations. (We won't touch this side in this course — but it's there if you want it later.)

What's the difference between Python and an Excel formula?

Excel formulas live inside a cell. They look at the cells around them and compute a single value. They're a single-step calculator.

A piece of Python — usually called a script — lives in its own file. It can do a thousand things one after another: open a file, change some numbers, save the file, then open another file, then send an email. It's a recipe with as many steps as you want.

The new =PY() formula in Excel mashes the two together: you write a few lines of Python inside a spreadsheet cell and you get a value back, just like a formula. We cover that in Module 8.

What this course will (and won't) teach you

We focus 100% on Python for spreadsheet-style work. That means: data, files, automation, reports, charts, and the new =PY() in Excel. We don't cover web apps, game development, or computer science theory. If you want those later, you'll have plenty of Python background to pick them up easily.