Problem No 10
Convert a list to a set to remove duplicates
Easy≈ 8 minute session
Lesson guide
What this Python exercise practices
Convert a list to a set to remove duplicates is a beginner practice lesson that focuses on lists, iteration, filtering. It is designed to be solved in about 8 minutes with examples, starter code, and test feedback.
Prerequisites
- Python variables
- List values
- Basic indexing
Difficulty and time
- Level
- Beginner
- Estimated time
- 8 minutes
Practice path
Summary
Learn how to remove duplicate items from a list by converting it to a set and returning a canonical sorted result.
Problem statement
Given a list of hashable and comparable items, remove any duplicates by converting the list to a set, then return the unique items as a sorted list. This provides a canonical ordering for testing and predictable output.
Task
Write a function that removes duplicates from a list by using a set and returns a sorted list of the unique items.
Examples
Remove duplicates from integers
Input
list_to_set([3, 1, 2, 3])
Output
[1, 2, 3]
Explanation
Convert to a set to drop the duplicate 3, then sort to get a consistent list [1, 2, 3].
Input format
A single list of hashable, comparable items (numbers or strings).
Output format
A sorted list containing each unique item from the input exactly once.
Constraints
Elements in the list are hashable and mutually comparable (so sorting works). List length can be large (e.g., up to 100000), so aim for reasonable time/space usage.
Samples
Sample input 0
[1, 1, 2, 2, 3]
Sample output 0
[1, 2, 3]
Explanation 0
Duplicates removed and result sorted.
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