合拼两个有序列表

listA = [1,2,5,9,34,99]
listB = [3,6,15,59,88]

def fun(arg1,arg2):
    tmp = []
    while len(arg1) > 0 and len(arg2) > 0:
        if arg1[0] > arg2[0]:
            tmp.append(arg2[0])
            # del arg2[0]
            arg2.pop(0)
        else:
            tmp.append(arg1[0])
            del arg1[0]
    tmp.extend(arg1)
    tmp.extend(arg2)
    return tmp


print(fun(listA,listB))