Index and slice
- Python course
- Beginner
- Lesson 54/116
- 4 min
Learn access with list[i] and list[a:b].
Index and slice
We access list items by index. Indexes start at 0: fruits[0] is the first item. A slice takes a part: fruits[0:2] gives the first two items.
fruits = ["Apple", "Pear", "Banana"]
print(fruits[0]) # Apple
print(fruits[0:2]) # ['Apple', 'Pear']
print(fruits[-1]) # BananaA slice is [start:stop]; stop is excluded. Negative indexes count from the end.
Slice forms
Slices come in three forms:
fruits[1:3]— from 1 to 3 (3 excluded)fruits[:2]— from start to 2fruits[1:]— from 1 to end
An empty start/stop means the list start/end. This short form is very handy.
Slicing is handy for extracting a sublist; the original list is unchanged.
Slicing is handy for extracting a sublist; the original list is unchanged.
Slicing is handy for extracting a sublist; the original list is unchanged.
Slicing is handy for extracting a sublist; the original list is unchanged.
Practice Print slices
Assign fruits = ["Apple", "Pear", "Banana", "Strawberry"]. Print print(fruits[0:2]) and print(fruits[2:]).
Starter code
# Use slicesSample solution
fruits = ["Apple", "Pear", "Banana", "Strawberry"]
print(fruits[0:2])
print(fruits[2:])Expected output
['Apple', 'Pear'] ['Banana', 'Strawberry']
Questions and answers
Review the lesson questions together with their answers. To test yourself, solve the lesson interactively.
1 In fruits = ["a", "b", "c"], what is fruits[1]?
- "b" Correct answer
- "a"
- "c"
- 1
Explanation: Index 1 is the second item: 'b'.
2 Complete the slice
fruits = ["Apple", "Pear", "Banana"]
print(fruits[____:2])fruits = ["Apple", "Pear", "Banana"]
print(fruits[0:2])Explanation: fruits[0:2] gives the first two items.
3 Match the slice forms
| Term | Meaning |
|---|---|
[0:2] |
First two |
[:2] |
Start to 2 |
[2:] |
2 to end |
[-1] |
Last item |