# Write a Python Program for Iterative Merge Sort # Recursive Python Program for merge sort  def merge(left, right):    if not len(left) or not len(right):        return left or right      result = []    i, j = 0, 0    while (len(result) < len(left) + len(right)):        if left[i] < right[j]:            result.append(left[i])            i+= 1        else:            result.append(right[j])            j+= 1        if i == len(left) or j == len(right):            result.extend(left[i:] or right[j:])            break       return result  def mergesort(list):    if len(list) < 2:        return list      middle = len(list)/2    left = mergesort(list[:middle])    right = mergesort(list[middle:])      return merge(left, right)      seq = [12, 11, 13, 5, 6, 7]print("Given array is")print(seq); print("\n")print("Sorted array is")print(mergesort(seq))  # Code Contributed by Mohit Gupta_OMG 