diff --git a/divide_and_conquer/quicksort.py b/divide_and_conquer/quicksort.py
index d40a905a2..87ccad4c9 100644
--- a/divide_and_conquer/quicksort.py
+++ b/divide_and_conquer/quicksort.py
@@ -1,5 +1,6 @@
 from __future__ import annotations
 
+
 def partition(array: list, start: int, end: int) -> int:
     """Helper function for Quick Sort.
 
@@ -22,7 +23,7 @@ def partition(array: list, start: int, end: int) -> int:
     >>> array
     []
     """
-    if not array: 
+    if not array:
         return 0
     pivot = array[end]
     index = start - 1
@@ -30,8 +31,9 @@ def partition(array: list, start: int, end: int) -> int:
         if array[j] <= pivot:
             index += 1
             array[index], array[j] = array[j], array[index]
-    array[index+1], array[end] = array[end], array[index+1]
-    return index+1
+    array[index + 1], array[end] = array[end], array[index + 1]
+    return index + 1
+
 
 def quicksort(array, start, end):
     """Returns a list of sorted array elements using Quick Sort.
@@ -61,9 +63,11 @@ def quicksort(array, start, end):
     """
     if start < end:
         partition_index = partition(array, start, end)
-        quicksort(array, start, partition_index-1)
-        quicksort(array, partition_index+1, end)
+        quicksort(array, start, partition_index - 1)
+        quicksort(array, partition_index + 1, end)
+
 
 if __name__ == "__main__":
     import doctest
+
     doctest.testmod()