merge sort implementation

Sorting/merge_sort.py

@@ -0,0 +1,57 @@
+"""
+
+Sorting a list of numbers with merge sort algorithm.
+
+"""
+
+
+def merge_sort(array, left_index, right_index):
+    if left_index >= right_index:
+        return
+
+    middle = (left_index + right_index)//2
+    merge_sort(array, left_index, middle)
+    merge_sort(array, middle + 1, right_index)
+    merge(array, left_index, right_index, middle)
+
+
+def merge(array, left_index, right_index, middle):
+    left_copy = array[left_index:middle + 1]
+    right_copy = array[middle+1:right_index+1]
+
+
+    left_copy_index = 0
+    right_copy_index = 0
+    sorted_index = left_index
+
+
+    while left_copy_index < len(left_copy) and right_copy_index < len(right_copy):
+
+
+        if left_copy[left_copy_index] <= right_copy[right_copy_index]:
+            array[sorted_index] = left_copy[left_copy_index]
+            left_copy_index = left_copy_index + 1
+        # Opposite from above
+        else:
+            array[sorted_index] = right_copy[right_copy_index]
+            right_copy_index = right_copy_index + 1
+
+
+        sorted_index = sorted_index + 1
+
+    while left_copy_index < len(left_copy):
+        array[sorted_index] = left_copy[left_copy_index]
+        left_copy_index = left_copy_index + 1
+        sorted_index = sorted_index + 1
+
+    while right_copy_index < len(right_copy):
+        array[sorted_index] = right_copy[right_copy_index]
+        right_copy_index = right_copy_index + 1
+        sorted_index = sorted_index + 1
+
+
+print("enter the numbers")
+arr = list(map(int, input().split(' ')))
+merge_sort(arr, 0, len(arr)-1)
+print(arr)
+