3.1 · Python Setup

Goal: install Python and run your first script.

Choose an editor

Three good free options:

Tool	Best for	Notes
Thonny	Absolute beginners	Tiny IDE with great debugger
VS Code	Long-term use	Powerful, extensible
PyCharm Community	Larger projects	Heavier, ideal for SBA

Install Python

1. Visit https://www.python.org/downloads/
2. Pick the latest stable 3.x version (3.11 or newer is fine).
3. During install on Windows, check "Add Python to PATH".

Verify the install

Open a terminal (Command Prompt on Windows, Terminal on macOS / Linux):

python --version
# Python 3.11.6

If it works, you're set.

Your first program

Create hello.py:

print("Hello, HKDSE ICT!")

Run it:

python hello.py

Output:

Hello, HKDSE ICT!

Running interactively

Type python in the terminal to enter the REPL:

>>> 2 + 3
5
>>> name = "Alice"
>>> print(name)
Alice
>>> exit()

The REPL is great for trying snippets.

Sample script · Greet by name

name = input("What is your name? ")
print(f"Hello, {name}!")

The f"…" syntax is a format string that lets you embed expressions inside text.

Common student mistakes

• Forgetting to put quotes around strings: print(Hello) → NameError.
• Mixing Python 2 syntax (print "x") with Python 3 (print("x")).
• Saving the file with the wrong extension.

Next steps

• Open Thonny or VS Code.
• Type, save, run the sample scripts above.

➡️ Next: 3.2 Variables & Operators