Queue Data Structure in Python
A queue removes values in the same order they were added, which is useful for scheduling and breadth-first search.
What is Queue Data Structure?
A queue removes values in the same order they were added, which is useful for scheduling and breadth-first search.
Implement an efficient first-in, first-out queue with collections.deque.
When should you use it?
- Practice problem solving and data structures.
- Process data when every algorithm step must be explicit.
- Prepare for programming exercises, exams, and interviews.
Example code
main.py
from collections import deque
queue = deque(["first", "second"])
queue.append("third")
print("served:", queue.popleft())
print("waiting:", list(queue))Expected output
served: first
waiting: ['second', 'third']How it works
Deque appends at the right and removes from the left in O(1) time, unlike removing the first value from a list.
Change the values and run the program in the CodeUtility online Python compiler without installing Python locally.
Practice exercises
Modify the runnable example with the exercises below to build understanding beyond copying the result.
- Try empty, single-item, and duplicate-value inputs.
- Print state after every step to observe the algorithm.
- Benchmark 100, 1,000, and 10,000 items, then compare another approach.