Your First Program
Write a real script, run it, and change it. Use any text editor — Notepad works, though an editor that numbers lines (VS Code, Notepad++) makes life easier later.
(Commands below use python on Windows, python3 on Mac/Linux.)
1. The one-liner
Open a terminal and run Python with a command directly:
python -c "print('Hello, world!')"
Check: it prints Hello, world!. The -c flag means "run this
code right now." print() displays whatever you give it.
2. A script file
One-liners get old fast. Create a file called hello.py containing:
print("Hello, world!")
Run it:
python hello.py
Check: same greeting. A script is just commands saved in a file — Python runs them top to bottom.
3. Make it yours
Change the file to:
name = "Ada"
print("Hello,", name)
Run it again.
Check: it prints Hello, Ada. You just used a variable — a
named box holding a value. See Variables and Types.
4. Take input
name = input("Your name? ")
print("Hello,", name)
Check: the program waits, you type your name, it greets you.
input() pauses for the keyboard and hands you what was typed — always
as text, even if the user types digits.
What to try next
- Variables and Types: strings, numbers, lists.
- Control Flow: decisions and repetition.
- Functions: reusable chunks.