What Can Change: List Copies and Tuples
Python Programming 2 Grades 9–12 4-day lesson 29 deliverables Teach students how Python names, lists and copies fit together, and when values should never change. Students draw arrows from names to lists, test sharing with is and ==, and make a real copy with [:]. They fix list tools that change the caller's list, write an undo tool and use tuples and unpacking to keep values together.
● Instant download · Lifetime access · Editable & print-ready
Print + digitalPDF, PowerPoint, Word & Google
Answer keysA key for every page
Built-in assessmentExit tickets + lesson quiz
45-minute daysEvery day planned and timed
Short coding levels practice this lesson in CodeGrove, our code lab that runs in the browser. Students write the program, run it and check it, with no account and nothing to install. Use them with the lesson or as practice later.
See the levelsWhat does this lesson cover?
When one list has two names, a change through one name shows up through the other, and students are surprised. This lesson draws the arrows first. Then students copy a list before a function changes it and learn that a tuple cannot be changed at all.
The try-its on Days 1 and 3, the lab on Day 2 and the quiz task on Day 4 run online in CodeGrove, our in-browser code lab, so students need a computer or tablet on those days. The Copy Trouble level practices copying a list before a function changes it, telling a shared list from a copy with is and ==, and keeping values together in tuples. CodeGrove is free, with no accounts, sign-ins or installs.
Copy Trouble
Students fix list tools that change the list they get and write an undo tool in CodeGrove.
Everything that's included
00 Start Here
- READ FIRST: every file in the lesson and when you use it
- Teacher Guide and Pacing: the plan for each day, what to print and how to grade
- Skills map: which standards each day teaches
01 Present
- One editable PowerPoint deck for all four days, 32 slides, with speaker notes
- Slide script: the speaker notes, printed
- Bell ringers: a short warm-up for each day
02 Student Handouts
- Guided notes: one packet for all four days, in PDF and editable Word. Students fill in the blanks during the slides, with the word bank on the page
- Vocab slip: the lesson's words and what they mean, on one page
03 Labs
- Copy Trouble: students fix list tools that change the list they get and write an undo tool in CodeGrove
04 Activities
- One List or Two?: students draw arrows from names to lists and write what `is` and `==` give, on paper with computers closed
- List or Tuple?: students decide if each kind of data fits a list or a tuple and explain two of their choices, on paper with computers closed
- Quiz task: students add a tuple to a list in CodeGrove, working alone, and then take the lesson quiz on paper
05 Assessment
- Exit tickets: quick questions that show who needs more help
- Lesson quiz: 8 multiple-choice questions and 2 written answers about all four days, on paper
06 Answer Keys
- 6 answer key files: a key for each day (its bell ringer, notes and exit ticket) and the activity and lab keys, plus the quiz key
Digital: Google Forms™ + Google Slides™
- 5 Google Forms™ of the exit tickets and the quiz, ready to copy into your Drive
- The multiple choice grades itself, and you grade the written answers
- A Google Slides™ copy of the deck, with the same slides and speaker notes, for Google Classroom™
- Give a Form that asks students to read code only on school-managed Chromebooks in locked mode, and use the paper version on other devices
Online: CodeGrove
- In CodeGrove: the lab on Day 2 (Copy Trouble) and the quiz task on Day 4, on a computer or tablet for each student
- Try-its on Days 1 and 3: students practice the new code in CodeGrove, and nothing is turned in
- Free to use, with no accounts, sign-ins or installs
Why teachers love this lesson
Arrows show who shares a listStudents see that b = a gives one list two names and that a[:] makes a real copy. They check with is and ==.
Tuples keep values togetherStudents decide whether each kind of data fits a list or a tuple. They unpack a tuple to give each value its own name.
Print and digitalEvery page is a print-ready PDF, and the Google Forms™ and Google Slides™ let you teach the same lesson in Google Classroom™.
Real online labsStudents write and run real Python in CodeGrove, our in-browser code lab, on a computer or tablet, with no accounts or installs.
A key for every pageEvery day has its own answer key, and every written question has a sample answer and what to look for.
Every day fits a 45-minute classEach day's plan is timed activity by activity against real reading and writing speeds.
What Teachers Say
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How do I get the files after I buy?
Instant download right after checkout: PowerPoint and Word files you can edit, print-ready PDFs, and links that copy the Google Forms™ and Google Slides™ into your Drive.
Can I buy the whole unit or course instead?
Yes. This lesson is part of the Unit 3 bundle and the complete Python Programming 2 course. Both cost less than buying the lessons one at a time.
Is this AP Computer Science?
No. It is a full-year, non-AP second course in Python for grades 9 to 12. For AP, see our AP Computer Science A and AP CSP courses.
What should students know before this lesson?
Students know the list methods, the four loop patterns and how to return two values from a function.
Do students need computers?
Yes, on the CodeGrove days. Each student needs a computer or tablet that's online, and CodeGrove needs no account or install. The bell ringers, notes, exit tickets and quiz are on paper.
What formats are the files in?
Every page is a print-ready PDF. The slides are an editable PowerPoint and the guided notes an editable Word file. The exit tickets and the quiz also come as Google Forms™, and the deck as Google Slides™.
Which standards does it cover?
Written for Florida's Intermediate Programming course (9007220). The skills map in the lesson shows which standards each day teaches.