Day 04: Values, binding, and observable text

Instructions

Study source: within this activity's existing reading/practice time, use Automate the Boring Stuff with Python, 3rd edition, Chapter 1; Practice Questions; Appendix B answers, then explain one connection to the local task in your own words. Keep the local exercise and acceptance checks; use its original explanation if the external source is unavailable. Required work: Save the following as census.py. Before running it, write a prediction for each output line. Then run python3 census.py, capture the exact output, and compare it with your prediction.

for value in [0, "0", "", None]:
    print(repr(value), type(value).__name__, bool(value))
print("0" == 0, int("0") == 0)

Explain in one or two sentences why "0" (text) and 0 (integer) print differently with repr(), have different types, and have different truth values.

Optional work: only after the required evidence is complete, add one more value of your choice (for example 0.0 or "False") to the list, predict its row, and run again.

Instructions

Required work: Save the following as binding.py. Before running it, write a prediction for each of the three output lines and draw one arrow per assignment from the name to the list object it refers to.

x = ["draft"]
y = x
x = ["replaced"]
print(y)
print(x)
print(x is y)

Run python3 binding.py, capture the exact output, and explain which binding changed on line 3 and which did not.

Optional work: only after the required evidence is complete, add print(id(x), id(y)) before and after line 3 and describe what changes.

Instructions

Required work: Create a practice repository with the original, misleading report:

git init report-demo && cd report-demo
printf 'count = "0"\nprint("count=" + count)\n' > report.py
git add report.py && git commit -m "Add count report"
python3 report.py

The program prints count=0, which hides that count is the text "0", not the number 0. The original report.py is:

count = "0"
print("count=" + count)

Ask your agent to change only the print line in report.py so it shows the repr and the type of count. Declare the permission you gave (for example: edit report.py only, no commits). Before running anything, predict what the new output will be. Then review and commit yourself:

git status --short
git diff -- report.py
git diff --check
python3 report.py
git add report.py
git commit -m "Show repr and type in count report"
git status --short

If git status lists any file other than report.py (for example ?? notes.txt), it is an unrelated edit: do not stage it; delete or restore it before committing.

Optional work: only after the required evidence is complete, ask the agent to also print bool(count) and review that second diff the same way.

Instructions

Required work: Without AI, write your prediction for every output line of the three snippets below before running any of them. Then run each snippet (for example as a.py, b.py, c.py), capture the exact output, and mark each line as match or mismatch. Explain the root cause of one mismatch; if every prediction matched, explain the snippet you found hardest.

Snippet A:

print(repr(None), repr("None"), None == "None")

Snippet B:

a = "draft"
b = a
a = a + "!"
print(a, b)

Snippet C:

items = ["draft"]
alias = items
items = items + ["final"]
print(alias, items)
print(alias is items)

Optional work: only after the required evidence is complete, change one input in one snippet (for example replace "!" with "?" in Snippet B), predict, and run it again.