algorithm stuty - merge sort

01 merge sort - python

def merge(A, B):
    C = []
    la = len(A)
    lb = len(B)
    ln = la + lb
    j = 0
    k = 0

    for i in range(ln):
        if j >= la:
            C.append(B[k])
            k += 1
            continue;
        if k >= lb:
            C.append(A[j])
            j += 1
            continue;
        if A[j] > B[k]:
            C.append(B[k])
            k += 1
        else:
            C.append(A[j])
            j += 1

    return C

def merge_sort(array):
    ln = len(array)
    mid = ln // 2

    if ln <= 1:
        return array

    left = merge_sort(array[:mid])
    right = merge_sort(array[mid:])

    return merge(left, right)

if __name__ == '__main__':
    import random

    L = [random.randrange(10, 99) for x in range(20)]
    print merge_sort(L)