python: merge sort

def mergeSort(array):
    if len(array) > 1:
        r = len(array)//2
        left_half = array[:r]
        right_half = array[r:]
        i = j = k = 0
        
        mergeSort(right_half)
        mergeSort(left_half)
        
        while (i < len(left_half) and j < len(right_half)):
            if left_half[i] <= right_half[j]:
                print("array", k, left_half[i])
                array[k] = left_half[i]
                i = i + 1
            else:
                array[k] = right_half[j]
                j = j + 1
            k = k + 1
            
        while (i < len(left_half)):
            #print("left array", k, left_half[i])
            array[k] = left_half[i]
            i = i + 1
            k = k + 1
        
        while (j < len(right_half)):
           # print("right array", k, right_half[j])
            array[k] = right_half[j]
            j = j + 1
            k = k + 1