Week 11 Coding Lab: Tidying a Soccer League's Sign-Up Texts

Part 1 — The Big Picture

This week you learned that a string method hands back a new value and never changes the string it is called on, that split makes a list and join makes a string, that find hands back a position or -1 and never True or False, and that replace and count work on every match. In this lab you put those ideas to work on the sign-up texts of an illustrative youth soccer league. You predict what six short programs print, run them, and study every gap between your prediction and the run. Then you read three broken programs, fix each with the smallest change that works, write a short program of your own that counts yes replies, and check a chatbot's answers about the same texts by running the code, because a chatbot predicts likely text and does not run your program.

Time budget: Plan for about 90 minutes.

Part 2 — The Task

Guiding question: For the league's sign-up texts, which of these six predictions about what a string method hands back will you get wrong, and how will each run show you the difference between a new string and the old one?

Workshop data: League sign-up texts: six short programs and three broken programs

Source: Six short Python programs and three broken programs about an illustrative youth soccer league's sign-up texts, written for this lab and printed in full in Part 4; the league, its teams, and its players are invented and describe no real group or person.

• Rows: 9 short programs in all: 6 programs to trace in the first table and 3 broken programs in the second table
• Language: Python 3, run in a free browser runner; no file to download and nothing to install
• Context: an illustrative youth soccer league with team names, age groups, positions, and typed sign-up replies

Part 3 — Materials & Procedure

Tools and materials

• A free browser-based Python runner (an online editor that runs Python 3 with no account and nothing to install), Python Tutor at pythontutor.com for step-by-step visualization, the official Python documentation at docs.python.org, and one approved chatbot used as a pair-programmer whose code the student runs before trusting

Ways of working

• write-run-and-verify
• trace-and-predict-output
• find-and-fix-the-bug

Procedure

1. Open a free browser Python runner in one tab and Python Tutor at pythontutor.com in another. In the runner, delete any sample code so the editor is blank. Tool: A free browser-based Python runner (an online editor that runs Python 3 with no account and nothing to install), Python Tutor at pythontutor.com for step-by-step visualization, the official Python documentation at docs.python.org, and one approved chatbot used as a pair-programmer whose code the student runs before trusting. Check: An empty editor with a Run button and a separate output panel.
2. In the first table in Part 4, write your prediction for each of the six programs before you run anything. Then type each program into the runner exactly as printed, press Run, and copy the output into the Actual output column, keeping every space and quotation mark. Tool: A free browser-based Python runner (an online editor that runs Python 3 with no account and nothing to install), Python Tutor at pythontutor.com for step-by-step visualization, the official Python documentation at docs.python.org, and one approved chatbot used as a pair-programmer whose code the student runs before trusting. Check: Six actual outputs, one per row, each copied character for character from the output panel; at least one is likely to differ from your prediction.
3. Type each broken program from the second table into the runner and press Run. For an error, scroll to the bottom of the error message and copy the error type from its last line. For a program that runs, compare what it printed with what its description says it should print. Tool: A free browser-based Python runner (an online editor that runs Python 3 with no account and nothing to install), Python Tutor at pythontutor.com for step-by-step visualization, the official Python documentation at docs.python.org, and one approved chatbot used as a pair-programmer whose code the student runs before trusting. Check: The second table shows what each broken program printed, or the error type on its last line; two of the three run without any error but print the wrong thing.
4. Fix each broken program with the smallest change that makes it do what its description in Part 4 says, run the fixed version, and record the new output. Tool: A free browser-based Python runner (an online editor that runs Python 3 with no account and nothing to install), Python Tutor at pythontutor.com for step-by-step visualization, the official Python documentation at docs.python.org, and one approved chatbot used as a pair-programmer whose code the student runs before trusting. Check: Each fixed program runs without an error and prints the reply, the age, or the team its description asks for.
5. Paste the program from Bug 1 of the second table into Python Tutor, click the button to visualize it, and step forward one line at a time. Watch whether the value shown for the name reply ever changes, then step through your fixed version and compare. Tool: A free browser-based Python runner (an online editor that runs Python 3 with no account and nothing to install), Python Tutor at pythontutor.com for step-by-step visualization, the official Python documentation at docs.python.org, and one approved chatbot used as a pair-programmer whose code the student runs before trusting. Check: In the broken version reply keeps holding the original text with its spaces; in the fixed version reply holds a new string after the assignment.
6. Write your own short program: start with the list of replies Yes, yes with a space in front, YES with a space after, and no, then use a for loop, strip, lower, and a counter to count how many replies say yes. Predict its output, run it, and fill in the third table. Tool: A free browser-based Python runner (an online editor that runs Python 3 with no account and nothing to install), Python Tutor at pythontutor.com for step-by-step visualization, the official Python documentation at docs.python.org, and one approved chatbot used as a pair-programmer whose code the student runs before trusting. Check: A short program that runs without an error, with your predicted and actual output side by side.
7. Open your approved chatbot, paste the critique prompt from Part 6 as one message, then check each of its claims by running the code it talks about. If you are using the equivalent route, mark up the printed flawed analysis in the same way. Tool: A free browser-based Python runner (an online editor that runs Python 3 with no account and nothing to install), Python Tutor at pythontutor.com for step-by-step visualization, the official Python documentation at docs.python.org, and one approved chatbot used as a pair-programmer whose code the student runs before trusting. Check: The fourth table lists each chatbot claim, what your run showed, and a correction wherever the two disagree.

Fallback route

When to use it: Use this route if your browser Python runner will not open or will not run code.

Run every program in Python Tutor instead, which also runs Python 3 in the browser: paste each program, click the button to visualize it, and step to the end to read its output or its error. Complete every table, analysis question, and the critique step, and submit the same items for equal credit.

This route earns the same credit as the primary route.

Part 4 — The Scaffold

Predict first and run second, so the gap between the two columns is your own evidence of what each method hands back.

Student scaffold table 1

Program	Your prediction	Actual output from the run	Same or different?
msg = " Tigers, U10 ", then print(msg.strip())
team = "tigers", then team.upper() on its own line, then print(team)
line = "goalie,9,Tigers", then print(line.split(","))
print("U10 Tigers".find("T"))
print("red,red,blue".count("red")), then print("red,red,blue".replace("red", "green"))
words = "practice is at the field at five".split(), then print(len(words)), then print("-".join(["U8", "U10", "U12"]))

Read each broken program from its run before you change a single character.

Student scaffold table 2

Broken program and what it should do	What printed, or the error type on the last line	Your one-change fix	Output after the fix
Bug 1, should print YES with no spaces: reply = " yes ", then reply.strip().upper() on its own line, then print(reply)
Bug 2, should print 10, a player's age next season: parts = "goalie,9,Tigers".split(","), then print(parts[1] + 1)
Bug 3, should print Tigers team: signup = "Tigers, U10", then if signup.find("Tigers"): with print("Tigers team") and else: with print("other team")

Write your own small program, then let the run confirm or correct what you expected it to print.

Student scaffold table 3

Line you wrote	Output you expected	Output of the run
Line 1
Line 2
Line 3
Line 4
Line 5
Line 6

Check every chatbot claim against a run so the run, not the chatbot, has the last word.

Student scaffold table 4

Chatbot claim, quoted	What your run showed	Correct as stated, or your correction

Part 5 — Analysis Questions

1. Which of your six predictions in the first table differed from the run? For each one, write the step-by-step trace that reaches the actual output and name the rule that explains the gap, such as a method handing back a new string, split cutting only where it is told, or positions counting from 0.
2. In step 5, what did Python Tutor show the name reply holding before and after the fix in Bug 1? Explain what that tells you about whether a string method can change the string it is called on.
3. Bugs 1 and 3 run without any error message but print the wrong thing, while Bug 2 stops with an error. Explain why Bugs 1 and 3 are logic errors, and name the error type Bug 2 raised and why the program raised it.
4. Choose one: (a) describe how you would decide whether to trust a chatbot's claim about what a string method hands back, using one claim from your critique as the example; or (b) describe how predicting before running changed what you noticed about find or split in this lab, using one row of your first table as the example.
5. Your yes-counting program was tested on four tidy replies. Name one kind of reply a real sign-up form could receive that your program would miscount, and say how you would check it by running more cases.

Part 6 — AI-Critique Moment

Choose one equal-credit critique route. Route A: ask an approved AI tool to critique your completed work, then check its response against your own evidence. Route B is the no-AI equivalent printed below.

Approved tools: Claude, Gemini, ChatGPT, Grok, Microsoft Copilot.

Prompt to paste:

I'm doing a beginner Python lab about tidying the sign-up texts for a youth soccer league, written for a class activity. Please do seven things, and keep each answer short. First, predict exactly what print("U10 Tigers".find("T")) prints. Second, predict what print("goalie,9,Tigers".split(",")) prints, and say in one sentence what type the 9 in that list is. Third, write one line that prints the first three letters of team = "Tigers" using a slice. Fourth, this program should print 10 but stops with an error; fix it: parts = "goalie,9,Tigers".split(",") then print(parts[1] + 1). Fifth, this program should print Tigers team but prints other team; fix it: signup = "Tigers, U10", then if signup.find("Tigers"): with print("Tigers team") and else: with print("other team"). Sixth, does "red,red,blue".replace("red", "green") change only the first red? Seventh, will reply.strip().lower() == "yes" be True for every reply that means yes, such as "Yes!"?

Test the response for these likely failures:

• Chatbots often count positions from 1 and predict that print("U10 Tigers".find("T")) prints 5.
• A chatbot may quote the right list, ['goalie', '9', 'Tigers'], and then explain that split turned the 9 into a number.
• Asked for the first three letters, a chatbot may write team[0:2] or team[1:4], forgetting that a slice leaves out its stop and starts at 0.
• A chatbot may fix the TypeError by writing print(parts[1] + "1"), which runs without an error but changes what the program does.
• A chatbot may fix the find bug by changing the test to if signup.find("Tigers") > 0: and call the program working without running it.
• A chatbot may claim that replace changes only the first match unless you pass an extra argument, inventing a default that Python does not have.
• A chatbot may say that strip and lower make every reply that means yes match, missing replies with punctuation such as Yes!.

Write 2-3 sentences that name one thing the chatbot got right and at least one claim you corrected, and for each correction give the output or error type your own run showed.

Equivalent route (no AI required)

No AI account is required for this lab. Instead of the chatbot, critique this flawed analysis, printed here in full: “print("U10 Tigers".find("T")) prints 5, because the T is the fifth character. print("goalie,9,Tigers".split(",")) prints a list in which split has already turned the 9 into a number. The first three letters of team = "Tigers" are team[0:2]. To fix the error in print(parts[1] + 1), write print(parts[1] + "1"); it now prints the age next season. To fix the find bug, write if signup.find("Tigers") > 0:; this version is working. replace changes only the first match, so "red,red,blue".replace("red", "green") gives green,red,blue. After strip and lower, every reply that means yes matches "yes", including Yes!.” Mark it up: quote each flawed sentence, run the code it describes in your browser Python runner, and write the corrected claim beside it with the run's output or error type as evidence. This route assesses the same objectives as the chatbot critique, namely predicting what a string method hands back, reading split and find correctly, slicing from position 0, and checking every claim about text by running it (Objective 7 and Objective 2), and it takes comparable effort, about 20 minutes of the lab. It is scored by the same rubric for the same credit, and its marked-up analysis replaces the chatbot report and share link in your submission. You do not need to say which route you chose.

Part 7 — What to Submit

• All four completed scaffold tables
• Written answers to all five analysis questions
• Your yes-counting program with its run output
• The chatbot critique report with its share link, or the equivalent route's marked-up flawed analysis

Deliverable:

A short Coding Lab report on an illustrative soccer league's sign-up texts: four completed tables (six predictions beside their runs, three broken programs read and fixed, your own yes-counting program, and the checked chatbot claims), written answers to five analysis questions, and a critique of a chatbot's answers to the same questions, or, on the equivalent route, a marked-up correction of the printed flawed analysis. Submit in any accessible file type or as a link; a recorded response may be submitted as audio or video with a transcript, or as text. Choose a written, recorded, or visual form for your answers, such as screen captures of your runs with a short note for each; every form is graded by the same rubric.

Rubric

The rubric below shows how each submitted part is evaluated; bands are full, partial, or none.

Workshop evaluation criteria

Criterion	Full	Partial	None
Predicting and running the six programs	All six predictions are recorded before the runs, and all six actual outputs match what the programs print, copied character for character, including the quotation marks in a printed list.	The table is mostly complete, but an actual output is missing or miscopied, or predictions appear to have been filled in after running.	No predictions or runs are recorded, or the outputs are invented rather than run.
Explaining the gaps between prediction and run	Every prediction that differed from its run is traced step by step to the actual output, with the governing rule named, such as a method handing back a new string, split cutting only at its separator, or positions counting from 0.	The gaps are listed, but a trace is missing or the rule behind a gap is not named.	No gap is explained, or the response blames the runner instead of the rule.
Finding and fixing the three bugs	Each bug is read correctly from its run: what printed or the error type, a one-change fix, and the fixed program's output, with Bugs 1 and 3 identified as logic errors and Bug 2 named by its error type, and the Bug 2 fix keeping the arithmetic.	Two of the three bugs are read and fixed correctly, or all three are fixed but an error type or the run evidence is missing.	The bugs are not attempted, or errors are named without running the programs.
Writing, running, and verifying a program	The yes-counting program runs without an error, uses strip and lower before it compares, and its expected and actual outputs are recorded side by side.	The program runs but misses one requirement, such as comparing without normalizing, or the expected or actual output is not recorded.	No program is submitted, or it was not run.
Critiquing the AI analysis or the printed flawed analysis	The chatbot's answers, or on the equivalent route the printed flawed analysis, are quoted and at least two claims are corrected with evidence from the student's own runs.	The critique names errors but corrects only one, or corrects without run evidence, on either route.	No critique is submitted on either route, or chatbot or flawed text is pasted without any checking.
Reflection and limitation	The chosen reflection option is answered with a specific example from this lab, and the limitation answer names a reply the program would miscount and a sensible way to check it.	The reflection or the limitation is general, without an example from this lab or a way to check it.	The reflection and limitation questions are not answered.

Quality Gate

• Every prediction in the first table was written before its program was run.
• Every actual output and error type is copied from your own run, never from memory or a chatbot.
• Each error is named by its type from the last line of the error message, not by the wording after the colon.
• Each fix changes as little as possible and its fixed program was run.
• No output, count, or claim is invented anywhere in the submission.
• The critique quotes the chatbot or the flawed analysis and corrects at least two claims with evidence from your runs.