Reading an error message and traceback
Name:
Date:
Class:
A
Quick Questions
Shade in the A or B circle for each question.
1. A traceback says 'NameError: name score is not defined' on line 7. What does this mean?
2. Where should you start looking for a bug when you read a traceback?
3. Which error type does this code cause?
print('Hello'
4. Which error type does this code cause?
print(total)
(total was never created)
5. Which error type does this code cause?
print('Age: ' + 15)
B
Match the Pairs
Draw a line connecting each item on the left to its match on the right.
| Left column | Right column | |
|---|---|---|
| 1NameError: name 'score' is not defined | AThe list only has positions 0 and 1, so index 2 does not exist. Use names[1] to get the last item. | |
| 2File "game.py", line 12, in <module> | BIndexError: list index out of range | |
| 3An IndexError means you asked for a list position that does not exist | CA SyntaxError means the code breaks Python's grammar rules. Here a closing bracket is missing, so add ) at the end of the line. | |
| 4A TypeError happens when you combine values of the wrong types, like a string and an integer | DPython met a variable name it has never seen, often from a typo or using it before it was created | |
| 5File "app.py", line 5 print("Hi" ^ SyntaxError: '(' was never closed | EThe traceback line that shows which file and which line number to start looking for the bug | |
| 6names = ['Ava', 'Ben'] print(names[2]) IndexError: list index out of range | FTypeError: can only concatenate str (not "int") to str |
C
Definitions
Traceback (most recent call last):
D
Fill in the Blanks
Complete each line of code by filling in the missing parts.
1.
_________: name 'scor' is not defined
2.
age = 15
print("Age: " + age)
_________: can only concatenate str
3.
colours = ["red", "blue"]
print(colours[5])
__________: list index out of range
4.
print("Hello"
___________: '(' was never closed
5.
File "main.py", ____ 3, in <module>
E
Spot the Error
Shade in the letter of the line that contains an error.
Question 1
A
score = 10
B
bonus = 5
C
total = score + bonnus
D
print(total)
Question 2
A
for i in range(3)
B
print(i)
C
print('Done')
Question 3
A
pets = ['cat', 'dog', 'fish']
B
print(pets[0])
C
print(pets[1])
D
print(pets[3])
Question 4
A
age = 15
B
msg = 'Age: ' + age
C
print(msg)
Question 5
A
name = 'Sam'
B
points = 3
C
print(name)
D
print(Points)
Answer Key
Reading an error message and traceback
Section A: Quick Questions
Q1
A — Python found a name on line 7 that was never created
Q2
A — At the line number the error message gives
Q3
A — SyntaxError
Q4
B — NameError
Q5
B — TypeError
Section B: Match the Pairs
Q1
NameError: name 'score' is not defined → Python met a variable name it has never seen, often from a typo or using it before it was created
Q2
File "game.py", line 12, in <module> → The traceback line that shows which file and which line number to start looking for the bug
Q3
An IndexError means you asked for a list position that does not exist → IndexError: list index out of range
Q4
A TypeError happens when you combine values of the wrong types, like a string and an integer → TypeError: can only concatenate str (not "int") to str
Q5
File "app.py", line 5
print("Hi"
^
SyntaxError: '(' was never closed → A SyntaxError means the code breaks Python's grammar rules. Here a closing bracket is missing, so add ) at the end of the line.
Q6
names = ['Ava', 'Ben']
print(names[2])
IndexError: list index out of range → The list only has positions 0 and 1, so index 2 does not exist. Use names[1] to get the last item.
Section C: Definitions
Q1
Traceback (most recent call last): — The start of Python's error report. It names the error type (like NameError) and the line number where it happened, so you know where to start looking for the bug.Section D: Fill in the Blanks
Q1
NameError: name 'scor' is not definedQ2
age = 15
print("Age: " + age)
TypeError: can only concatenate strQ3
colours = ["red", "blue"]
print(colours[5])
IndexError: list index out of rangeQ4
print("Hello"
SyntaxError: '(' was never closedQ5
File "main.py", line 3, in <module>Section E: Spot the Error
Q1
C — The traceback would say NameError: name 'bonnus' is not defined, on line 3. The variable is spelled bonus, so the line should be total = score + bonus.
Q2
A — A SyntaxError is reported on line 1 because the colon at the end of the for line is missing. It should be for i in range(3):
Q3
D — The list has 3 items, so the valid indexes are 0, 1 and 2. Index 3 gives IndexError: list index out of range on line 4. It should be pets[2].
Q4
B — You can't add a string and an integer. Python gives a TypeError on line 2. Convert the number with str(age).
Q5
D — Python is case-sensitive. The variable is points, not Points, so the traceback shows NameError on line 4. It should be print(points).