Lists – Indexing
Name:
Date:
Class:
A
Quick Questions
Shade in the A or B circle for each question.
1. colors = ['red','blue','green']\ncolors[0] returns?
2. colors = ['red','blue','green']\ncolors[-1] returns?
3. Can you change a list item by index?
4. nums = [10,20,30]\nnums[3] does what?
5. 'cat' in ['cat','dog'] returns?
B
Match the Pairs
Draw a line connecting each item on the left to its match on the right.
| Left column | Right column | |
|---|---|---|
| 1nums = [10, 20, 30] print(nums[3]) | AValid: Lists are mutable | |
| 2nums = [1, 2, 3] print(nums(0)) | BOutput: b | |
| 3nums = [5, 10, 15] nums[1] = 99 | CError: Use [] not () for indexing | |
| 4nums[-1] | DError: Index 3 out of range | |
| 5c = ['r','g','b'] print(c[0]) | EOutput: r | |
| 6c = ['r','g','b'] print(c[-1]) | FOk: Last item in list |
C
Definitions
list[0]
D
Fill in the Blanks
Complete each line of code by filling in the missing parts.
1.
colors = ['red', 'blue']
print(colors[_])
2.
nums = [10, 20, 30]
nums[_] = 99
3.
pets = ['cat', 'dog']
print('cat' __ pets)
4.
___ fruit in fruits:
print(fruit)
5.
colors = ['red', 'blue', 'green']
print(colors[__])
E
Spot the Error
Shade in the letter of the line that contains an error.
Question 1
A
colors = ['red', 'blue', 'green']
B
first = colors[0]
C
last = colors[3]
D
print(first, last)
Question 2
A
colors = ['red', 'blue']
B
first = colors(0)
C
print('First:', first)
D
print('Done')
Question 3
A
colors = ['red', 'blue']
B
first = colors['0']
C
print('First:', first)
D
print('Done')
Question 4
A
nums = [10, 20, 30]
B
nums(1) = 99
C
print('Updated:', nums)
D
print('Done')
Question 5
A
colors = ['red', 'blue']
B
for color in colors
C
print(color)
D
print('Done')
Answer Key
Lists – Indexing
Section A: Quick Questions
Q1
B — 'red'
Q2
A — 'green'
Q3
B — Yes lists are mutable
Q4
A — IndexError
Q5
A — True
Section B: Match the Pairs
Q1
nums = [10, 20, 30]
print(nums[3]) → Error: Index 3 out of range
Q2
nums = [1, 2, 3]
print(nums(0)) → Error: Use [] not () for indexing
Q3
nums = [5, 10, 15]
nums[1] = 99 → Valid: Lists are mutable
Q4
nums[-1] → Ok: Last item in list
Q5
c = ['r','g','b']
print(c[0]) → Output: r
Q6
c = ['r','g','b']
print(c[-1]) → Output: b
Section C: Definitions
Q1
list[0] — Access the first item in the list.~~list[-1]Section D: Fill in the Blanks
Q1
colors = ['red', 'blue']
print(colors[0])Q2
nums = [10, 20, 30]
nums[1] = 99Q3
pets = ['cat', 'dog']
print('cat' in pets)Q4
for fruit in fruits:
print(fruit)Q5
colors = ['red', 'blue', 'green']
print(colors[-1])Section E: Spot the Error
Q1
C — List has indices 0,1,2: index 3 is out of range
Q2
B — Use square brackets [] for indexing, not parentheses ()
Q3
B — Index must be an integer, not a string
Q4
B — Use square brackets for assignment: nums[1] = 99
Q5
B — Missing colon after the for statement