Python How ToLesson 152Free preview
Remove List Duplicates
This lesson is part of Python · All levels
Summary
There are several ways to remove duplicate elements from a list in Python, and the choice depends on whether the sequence should be maintained. The shortest way is to convert to the set and then back to the list, but that way you're tracking the original order. When the sequence is important, use dict.fromkeys() or manual iteration with a set of markers.
Key points
- The most concise, but the order of elements is uncertain.
- Delete duplicates while maintaining the order of first appearance.
- Manual method: iteration while marking elements that have already been seen on a set.
- The first element that appears is usually stored, the next one is discarded.
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