Update timsort.py

Author: theycallmemac

sorts/timsort.py

@@ -1,68 +1,81 @@
-def binary_search(the_array, item, start, end):
+def binary_search(lst, item, start, end):
     if start == end:
-        if the_array[start] > item:
+        if lst[start] > item:
             return start
         else:
             return start + 1
     if start > end:
         return start
 
-    mid = (start + end)/ 2
-    if the_array[mid] < item:
-        return binary_search(the_array, item, mid + 1, end)
-    elif the_array[mid] > item:
-        return binary_search(the_array, item, start, mid - 1)
+    mid = (start + end) // 2
+    if lst[mid] < item:
+        return binary_search(lst, item, mid + 1, end)
+    elif lst[mid] > item:
+        return binary_search(lst, item, start, mid - 1)
     else:
         return mid
 
 
-"""
-Insertion sort that the heap sort uses if the array size is small or if
-the size of the "run" is small
-"""
-def insertion_sort(the_array):
-    l = len(the_array)
-    for index in range(1, l):
-        value = the_array[index]
-        pos = binary_search(the_array, value, 0, index - 1)
-        the_array = the_array[:pos] + [value] + the_array[pos:index] + the_array[index+1:]
-    return the_array
+def insertion_sort(lst):
+    length = len(lst)
+
+    for index in range(1, length):
+        value = lst[index]
+        pos = binary_search(lst, value, 0, index - 1)
+        lst = lst[:pos] + [value] + lst[pos:index] + lst[index+1:]
+
+    return lst
+
 
 def merge(left, right):
-    """Takes two sorted lists and returns a single sorted list by comparing the
-    elements one at a time.
-    [1, 2, 3, 4, 5, 6]
-    """
     if not left:
         return right
+
     if not right:
         return left
+
     if left[0] < right[0]:
         return [left[0]] + merge(left[1:], right)
+
     return [right[0]] + merge(left, right[1:])
 
 
-def timsort(the_array):
+def timsort(lst):
     runs, sorted_runs = [], []
-    l = len(the_array)
-    new_run = [the_array[0]]
-    for i in range(1, l):
-        if i == l-1:
-            new_run.append(the_array[i])
+    length = len(lst)
+    new_run = [lst[0]]
+    sorted_array = []
+
+    for i in range(1, length):
+        if i == length - 1:
+            new_run.append(lst[i])
             runs.append(new_run)
             break
-        if the_array[i] < the_array[i-1]:
+
+        if lst[i] < lst[i - 1]:
             if not new_run:
-                runs.append([the_array[i-1]])
-                new_run.append(the_array[i])
+                runs.append([lst[i - 1]])
+                new_run.append(lst[i])
             else:
                 runs.append(new_run)
                 new_run = []
         else:
-            new_run.append(the_array[i])
-    for each in runs:
-        sorted_runs.append(insertion_sort(each))
-    sorted_array = []
+            new_run.append(lst[i])
+
+    for run in runs:
+        sorted_runs.append(insertion_sort(run))
+
     for run in sorted_runs:
         sorted_array = merge(sorted_array, run)
-print(sorted_array)
+
+    return sorted_array
+
+
+def main():
+
+    lst = [5,9,10,3,-4,5,178,92,46,-18,0,7]
+    sorted_lst = timsort(lst)
+    print(sorted_lst)
+
+if __name__ == '__main__':
+    main()