Setting a breakpoint

Name:

Date:

Class:

Quick Questions

Shade in the A or B circle for each question.

1. How do you set a breakpoint in most code editors?

A Click in the margin beside the line number

B Type the word breakpoint at the end of the line

2. What does a breakpoint do when the program runs in debug mode?

A Deletes that line so the program skips it

B Pauses the program at that line so you can inspect it

3. Which way of running your program will actually stop at a breakpoint?

A Running in debug mode

B Running normally with the standard Run button

4. Your loop gives a wrong total after several passes. Where is the best place to set a breakpoint?

A On the very first comment at the top of the file

B On the line inside the loop that updates the total

5. How do you remove a breakpoint?

A Click the same marker beside the line number again

B Delete the whole file and start again

Match the Pairs

Draw a line connecting each item on the left to its match on the right.

Left column		Right column
1Click beside line 12		ABreakpoint on line 8 with condition: i == 50
2Click the red dot on line 12		BA comment is not executed, so the program can never pause there. The breakpoint must go on a line of real code.
3Place a breakpoint on the line just before a suspected bug so you can inspect variables before the fault happens		CBreakpoints only pause the program when it is run in debug mode. A normal run ignores them, so the program never stops.
4A conditional breakpoint only pauses the program when a condition is true		Dtotal = total + price # breakpoint here, before the wrong total is printed
5Run the program normally, then expect it to pause at the breakpoint on line 5		ESets a breakpoint on line 12 so the program will pause there
6Set the breakpoint on a comment line: # check the total		FRemoves the breakpoint from line 12

Definitions

breakpoint

Fill in the Blanks

Complete each line of code by filling in the missing parts.

total = 0 __________() print(total)

if score _ 100: breakpoint()

if count __ 0: breakpoint() average = total / count

for mark in marks: total += mark __________()

for i in range(10): __ i == 7: breakpoint()

Spot the Error

Shade in the letter of the line that contains an error.

Question 1

A scores = [72, 85, 90

B total = 0

C for s in scores:

D breakpoint()

E total = total + s

Question 2

A price = 20

B qty = 3

C if qty > 2

D breakpoint()

E price = price * 0.9

Question 3

A for i in range(1, 11):

B total = i * 2

C if i == 5:

D breakpoint

E print(total)

Question 4

A def average(a, b):

B total = a + b

C Breakpoint()

D return total / 2

Question 5

A age = int(input("Age: "))

B if age = 0:

C breakpoint()

D print("Age is", age)

Answer Key

Setting a breakpoint

Section A: Quick Questions

A — Click in the margin beside the line number

B — Pauses the program at that line so you can inspect it

A — Running in debug mode

B — On the line inside the loop that updates the total

A — Click the same marker beside the line number again

Section B: Match the Pairs

Click beside line 12 → Sets a breakpoint on line 12 so the program will pause there

Click the red dot on line 12 → Removes the breakpoint from line 12

Place a breakpoint on the line just before a suspected bug so you can inspect variables before the fault happens → total = total + price # breakpoint here, before the wrong total is printed

A conditional breakpoint only pauses the program when a condition is true → Breakpoint on line 8 with condition: i == 50

Run the program normally, then expect it to pause at the breakpoint on line 5 → Breakpoints only pause the program when it is run in debug mode. A normal run ignores them, so the program never stops.

Set the breakpoint on a comment line: # check the total → A comment is not executed, so the program can never pause there. The breakpoint must go on a line of real code.

Section C: Definitions

breakpoint — A marker set on a line of code (click beside the line number) that pauses the program there in debug mode, so you can inspect variables and step through the code.

Section D: Fill in the Blanks

total = 0
breakpoint()
print(total)

if score > 100:
    breakpoint()

if count == 0:
    breakpoint()
average = total / count

for mark in marks:
    total += mark
    breakpoint()

for i in range(10):
    if i == 7:
        breakpoint()

Section E: Spot the Error

A — The list is missing its closing bracket ]. This is a syntax error, so the program never starts and never reaches the breakpoint. It should be scores = [72, 85, 90].

C — The if line is missing its colon. This is a syntax error, so the conditional breakpoint inside the if block can never be reached. It should be if qty > 2:

D — breakpoint is only named, not called. Without the brackets the program never pauses at i == 5. It should be breakpoint().

C — Python is case-sensitive. Breakpoint with a capital B is not a built-in function and causes a NameError. It should be breakpoint().

B — A single = assigns a value and is not allowed in an if condition, so it is a syntax error. To compare for the breakpoint condition use ==: if age == 0: