What is the performance of the deque in Python's collections module?

What is the performance of the deque in Python's collections module?

The deque (double-ended queue) in Python's collections module is optimized for fast appends and pops from both ends. It has O(1) time complexity for these operations, making it more efficient than lists for queue-like use cases.

How does it compare to a list in terms of performance?

While lists have O(1) time complexity for appending at the end, they have O(n) for inserting or removing elements at the beginning. In contrast, deques maintain O(1) for both ends, making them preferable for frequent insertions and deletions.

Are there any limitations to using deque?

Yes, deques have a fixed maximum size if you set one, and they may use more memory than lists for small collections due to their underlying data structure.

Can you give an example of when to use a deque?

Certainly! Use a deque when implementing a queue or a stack where you need to efficiently add and remove items from both ends, such as in breadth-first search algorithms.