What are the performance differences between lists and sets in Python?

What are the performance differences between lists and sets in Python?

Lists and sets have different performance characteristics. Lists are ordered and allow duplicates, while sets are unordered and do not allow duplicates. This affects their performance in operations like membership tests and insertions.

Can you explain how membership tests differ in performance?

Sure! Membership tests in lists have an average time complexity of O(n) because it may need to check each element. In contrast, sets have an average time complexity of O(1) due to their underlying hash table implementation.

What about insertion times for both data structures?

Inserting an element into a list is O(1) on average if you append, but O(n) if you need to insert at a specific position. For sets, insertion is O(1) on average, but can be O(n) in the worst case due to resizing.

Are there any scenarios where I should prefer lists over sets?

Yes, if you need to maintain order or allow duplicate elements, lists are the better choice. They are also useful when you need to access elements by index.