A Language and Its Interpreter

Scenario: You want the computer to greet a visitor, but it cannot understand ordinary English as a program.

New words, in plain English

• Python - a programming language designed to be readable
• Interpreter - the program that reads Python code and carries it out
• Source code - the instructions a person writes

Python source is text. The interpreter translates and runs it. Check the installed version with python3 --version; start the interactive interpreter with python3.

Analogy: A Python program is like a clear set of instructions for a careful helper: names label things, indentation groups steps, and errors explain where the helper became confused.

A small, real example

print("Hello, world!")
# A comment is a note for people.

Tip: Type examples instead of only reading them. Tiny experiments make the rules memorable.

Goal: Practice this idea in the py-variables-types challenge at /labs/python. Fix the broken program, run it yourself, then use check to prove the real end state.