Quick Sort Function

def quick_sort(arr):
if len(arr) <= 1:
return arr
pivot = arr[len(arr) // 2]
left = [x for x in arr if x < pivot]
middle = [x for x in arr if x == pivot]
right = [x for x in arr if x > pivot]
return quick_sort(left) + middle + quick_sort(right)

Function Annotation

Function Description

quick_sort(arr) - This function implements the Quick Sort algorithm. It takes a list of elements and returns a new list with the elements sorted in ascending order.

Parameters

• arr: A list of elements to be sorted. The elements in this list should be comparable with each other using comparison operators.

Return Value

• The function returns a new list containing the elements from the input list arr, sorted in ascending order.

Function Code

python
DownloadCopy code
1def quick_sort(arr):
2    if len(arr) <= 1:
3        return arr
4    pivot = arr[len(arr) // 2]
5    left = [x for x in arr if x < pivot]
6    middle = [x for x in arr if x == pivot]
7    right = [x for x in arr if x > pivot]
8    return quick_sort(left) + middle + quick_sort(right)

Unit Test Code

To test the quick_sort function, we can use Python's unittest framework. Below is a sample unit test:

python
DownloadCopy code
1import unittest
2
3class TestQuickSort(unittest.TestCase):
4    def test_quick_sort(self):
5        self.assertEqual(quick_sort([3, 6, 8, 10, 1, 2, 1]), [1, 1, 2, 3, 6, 8, 10])
6        self.assertEqual(quick_sort([]), [])
7        self.assertEqual(quick_sort([1]), [1])
8        self.assertEqual(quick_sort([1, 2, 3]), [1, 2, 3])
9        self.assertEqual(quick_sort([3, 2, 1]), [1, 2, 3])
10
11if __name__ == '__main__':
12    unittest.main()

To run these tests, simply copy the test code into a Python script where the quick_sort function is defined and execute the script.