以下是一个示例代码，用于实现不同时长的护士班次排班问题的解决方法：

class NurseSchedule:
    def __init__(self, nurses, shifts):
        self.nurses = nurses
        self.shifts = shifts

    def generate_schedule(self):
        schedule = {}

        for nurse in self.nurses:
            schedule[nurse] = []

        for shift in self.shifts:
            nurse = self._get_next_available_nurse(schedule)
            if nurse is None:
                raise Exception("No available nurses for shift " + shift)
            schedule[nurse].append(shift)

        return schedule

    def _get_next_available_nurse(self, schedule):
        for nurse in self.nurses:
            if len(schedule[nurse]) < self._get_max_shifts(nurse):
                return nurse
        return None

    def _get_max_shifts(self, nurse):
        # 根据护士的不同时长设定最大班次数
        if nurse.hourly_rate <= 8:
            return 3
        elif nurse.hourly_rate <= 10:
            return 2
        else:
            return 1

# 示例用法
nurses = [
    Nurse("Nurse A", 8),
    Nurse("Nurse B", 10),
    Nurse("Nurse C", 12)
]

shifts = ["Morning", "Afternoon", "Evening", "Night"]

schedule_generator = NurseSchedule(nurses, shifts)
schedule = schedule_generator.generate_schedule()

for nurse, shifts in schedule.items():
    print("Nurse:", nurse.name)
    print("Shifts:", shifts)
    print()

在上述示例代码中，Nurse 类代表一个护士对象，包含护士的姓名和小时工资率。NurseSchedule 类用于生成护士的班次排班表。在 generate_schedule 方法中，首先初始化一个空的排班表 schedule ，然后根据护士的不同时长设定确定每个护士的最大班次数，然后循环遍历每个班次，并通过 _get_next_available_nurse 方法获取下一个可用的护士进行排班。最终返回生成的排班表。

请注意，示例代码中使用了自定义的 Nurse 类和相应的属性和方法，你可以根据实际需求进行修改和补充。