Bubble Sort in Python
Bubble sort repeatedly compares neighboring values and swaps them when they are out of order.
What is Bubble Sort?
Bubble sort repeatedly compares neighboring values and swaps them when they are out of order.
Sort a Python list with bubble sort and an early-exit optimization.
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.
Bubble Sort in Python visualizer
O(n²)Use Play or Step to follow each comparison and data movement.
Example code
main.py
def bubble_sort(values):
result = values.copy()
for end in range(len(result) - 1, 0, -1):
swapped = False
for index in range(end):
if result[index] > result[index + 1]:
result[index], result[index + 1] = result[index + 1], result[index]
swapped = True
if not swapped:
break
return result
print(bubble_sort([5, 1, 4, 2, 8]))Expected output
[1, 2, 4, 5, 8]How it works
After every pass, the largest unsorted value reaches its final position. The swapped flag stops early when the list is already sorted. Worst-case time complexity is O(n²).
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.