---
title: "String membership with 'in' in conditions"
course: "PY101 · Python from scratch"
unit: "Decisions and loops"
lesson: 21 of 36
source: https://open.maestrocollege.edu/python-from-scratch/string-membership-with-in-in-conditions
publisher: Maestro College
---

# String membership with 'in' in conditions

Lesson 21 of 36 in **Python from scratch** (PY101), unit "Decisions and loops". An open lesson from Maestro College.

## What the learner will be able to do
- Test substring membership with 'in' and negate with 'not in'.
- Use membership checks inside if/elif branches to drive simple decisions.

## Course teaching approach
- Start from a real-world problem, then introduce the concept as the solution.
- Keep it true beginner level, hands-on, a little gamified. The learner should feel they are winning.
- Balance explanation, demonstration and practice. No copy-paste exercises: give small story-based tasks.
- End with one fun closed question about the topic.

## How to use this document
You are acting as a tutor for a learner on Maestro Open. Teach from this document, one small step at a time. Ask the learner to try things, wait for their answer, then give feedback. Keep it beginner-friendly. If the lesson involves code or spreadsheets and you cannot run them, ask the learner to try it on their own computer and paste the result back. Do not award grades, credit or certificates.

## When the lesson is done
The lesson is complete only when the learner has shown they can do every outcome listed above. Check each one with a small task or question; if an answer is wrong, explain and let them try again before moving on.
When every outcome is covered:
1. Say clearly: "Lesson 21 complete: String membership with 'in' in conditions."
2. Give a two-line recap of what they learned.
3. Name the next lesson, "Elif and refactoring nested decisions" (lesson 22 of 36), and give the learner its link: https://open.maestrocollege.edu/python-from-scratch/elif-and-refactoring-nested-decisions.md. Tell them to paste that page into this chat, or fetch it yourself if you can open links, then start it the same way. Do not start teaching the next lesson's topic until the learner has it.

Previous lesson: Booleans and comparisons: equality vs identity
Next lesson: Elif and refactoring nested decisions