Python Basics · Getting Started · Lesson 3 of 36
Running Python Files
Concept
Running Python Files
Python files end in .py and run top-to-bottom with the python filename.py command, or right here in the browser editor.
Indentation in Python isn't just a style choice — it's how the language knows which lines belong to which block, so consistent spacing (usually 4 spaces) actually matters for the code to run at all.
- Explain the core idea behind Running Python Files.
- Predict output before running a change.
- Test one realistic and one unusual input.
- Use the result to make the next decision.
- 1. Read one concept.
- 2. Change the example.
- 3. Run, compare, and explain.
- 4. Complete the challenge below.
Self-check before continuing
Without looking at the example, describe what changes when you modify one input in Running Python Files. Then reopen the editor and prove your explanation with a small test.
You are ready to continue when you can predict, test, and explain the result.
Your turn
Write a two-line script that stores your name in a variable and prints a greeting.
Ask about this lesson or your next move. The guide explains the path without taking the work away from you.
Ready for the next lesson?
Mark this lesson complete when you have finished the exercise.
Console