Getting Started · Lesson 1 of 39
What Is Python? A Friendly Introduction
Python is a programming language that reads almost like plain English. You write short instructions, and Python carries them out one line at a time. That simplicity is exactly why it has become the most popular language in the world, used by beginners on day one and by engineers at Google, Netflix, NASA and every AI lab you have heard of.
In this lesson
- What Python is, in one picture
- How Python turns your code into results
- Where Python is used in real jobs today
- What makes it easier than C or Java for a first language
Python in one sentence
Python is a high-level, interpreted, general-purpose programming language. Let us unpack those three words, because you will hear them in interviews:
- High-level – you think about the problem (names, prices, files), not about memory addresses or CPU registers. Python handles those details for you.
- Interpreted – you do not compile a separate program before running it. You run the file and Python executes it straight away.
- General-purpose – the same language builds websites, analyses data, trains AI models, automates boring office work and even controls robots.
Python was created by Guido van Rossum and first released in 1991. The name comes from the comedy show Monty Python's Flying Circus, not from the snake. Today it is developed in the open by the Python Software Foundation, and a new version comes out every October.
A first look at Python code
Here is a tiny program. Even if you have never coded before, you can probably guess what it does:
name = "Asha"
marks = [78, 91, 85]
average = sum(marks) / len(marks)
print(name, "scored an average of", round(average, 1))
if average >= 80:
print("Grade: A")Asha scored an average of 84.7 Grade: A
Compare that with the same idea in Java, where you need a class, a main method, type declarations and semicolons before anything happens. Python lets you focus on the logic, which is why universities, bootcamps and companies now teach it first.
How Python runs your code
When you press Run, a few things happen behind the scenes. You do not need to manage any of it, but knowing the steps helps you understand error messages later.
From your file to the result
- You write codeA plain text file such as
hello.py - Python compiles itInto bytecode – small, simple instructions (cached in
__pycache__) - The virtual machine runs itThe Python Virtual Machine executes the bytecode line by line
- You see the resultText on screen, a file saved, a web page served…
The program that does all this is called the interpreter. The standard one, downloaded from python.org, is written in C and is called CPython. When people say "install Python", this is what they mean.
Interview angle
"Is Python compiled or interpreted?" The honest answer is both: CPython first compiles your source to bytecode, then interprets that bytecode. It is called an interpreted language because you never run a separate compile step yourself.
Where Python is used
One language, many careers
Python
- AI & machine learningPyTorch, TensorFlow, scikit-learn, LLM apps and agents
- Data analysispandas, NumPy, Jupyter notebooks, charts with Matplotlib
- Web back-endsDjango, Flask and FastAPI power APIs and full websites
- Automation & scriptingRename files, fill spreadsheets, scrape sites, schedule tasks
- DevOps & cloudAnsible, AWS scripts, CI pipelines and monitoring tools
- Testingpytest and Playwright for automated testing
If you are aiming at AI, data science or backend roles, Python is not optional any more – it is the common language of the whole field.
Why Python is a great first language
| What you care about | Python | C / Java |
|---|---|---|
| Lines to print "Hello" | 1 | 5–6 |
| Declaring types | Not required (optional hints) | Required |
| Code blocks | Indentation | Curly braces and semicolons |
| Memory management | Automatic | Manual in C, automatic in Java |
| Ready-made libraries | 500,000+ on PyPI | Large, but more setup |
The trade-off is speed: pure Python runs slower than C. In practice this rarely matters, because the heavy lifting (maths, AI, databases) is done by libraries written in C, C++ or Rust that Python simply calls.
Key features at a glance
- Readable syntax – indentation shows structure, so messy code is hard to write.
- Dynamically typed – a variable gets its type from the value you give it.
- "Batteries included" – the standard library already handles files, dates, JSON, maths, email and much more.
- Cross-platform – the same script runs on Windows, macOS and Linux.
- Multi-paradigm – write simple scripts, object-oriented programs or functional-style code.
- Huge community – almost every error you hit has already been answered online.
Practice
Quick check
Python is called "high-level". What does that mean?
You work with ideas such as names, lists and files, and Python takes care of low-level details like memory addresses for you.
What is bytecode?
A simpler, intermediate form of your program that CPython creates before running it. The Python Virtual Machine executes the bytecode.
Name three areas where Python is widely used.
Any three of: AI and machine learning, data analysis, web back-ends, automation, DevOps and testing.
Is the language named after the snake?
No – after the British comedy group Monty Python.
Summary
- Python is a high-level, interpreted, general-purpose language created by Guido van Rossum.
- CPython compiles your code to bytecode and runs it on the Python Virtual Machine.
- It dominates AI, data, automation and back-end work, and is the easiest mainstream language to start with.
Next, you will install Python and an editor so you can run every example in this course on your own computer.
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