对方法递归的效果感到好奇吗

Question

我已经编写了一个实例方法，它使用递归来找到特定的解决方案。它工作得非常好，除了我退出if-elif块的时候。我在IF块中调用函数本身。而且，我只有一个返回语句。这个方法的输出对我来说很奇怪。以下是代码和输出：

def create_schedule(self):
    """
    Creates the day scedule for the crew based on the crew_dict passed.
    """   
    sched_output = ScheduleOutput()
    assigned_assignements = []
    for i in self.crew_list:
        assigned_assignements.extend(i.list_of_patients)

    rest_of_items = []
    for item in self.job.list_of_patients:
        if item not in assigned_assignements:
            rest_of_items.append(item)

    print("Rest of the items are:", len(rest_of_items))

    if len(rest_of_items) != 0:
        assignment = sorted(rest_of_items, key=lambda x: x.window_open)[0]
        # print("\nNext assignment to be taken ", assignment)
        output = self.next_task_eligibility(assignment, self.crew_list)
        if len(output) != 0:
            output_sorted = sorted(output, key=itemgetter(2))
            crew_to_assign = output_sorted[0][1]
            assignment.eta = output_sorted[0][4]
            assignment.etd = int(assignment.eta) + int(assignment.care_duration)
            crew = next((x for x in self.crew_list if x.crew_number == crew_to_assign), None)
            self.crew_list.remove(crew)
            crew.list_of_patients.append(assignment)
            crew.time_spent = assignment.etd
            self.crew_list.append(crew)

            self.create_schedule()
        else:
            print("*" * 80, "\n", "*" * 80, "\nWe were not able to assign a task so stopped.\n", "*" * 80, "\n", "*" * 80)

            sched_output.crew_output = self.crew_list
            sched_output.patients_left = len(rest_of_items)

    elif not rest_of_items:
        print("Fully solved.")
        sched_output.crew_output = self.crew_list
        sched_output.patients_left = 0

    print("After completely solving coming here.")
    return sched_output

这是输出：

Rest of the items are: 10
Rest of the items are: 9
Rest of the items are: 8
Rest of the items are: 7
Rest of the items are: 6
Rest of the items are: 5
Rest of the items are: 4
Rest of the items are: 3
Rest of the items are: 2
Rest of the items are: 1
Rest of the items are: 0
Fully solved.
After completely solving coming here.
After completely solving coming here.
After completely solving coming here.
After completely solving coming here.
After completely solving coming here.
After completely solving coming here.
After completely solving coming here.
After completely solving coming here.
After completely solving coming here.
After completely solving coming here.
After completely solving coming here.

我不明白的是，一旦我的剩余\u项列表为空，我就将数据分配给sched \u输出并返回它。但是，print语句的执行时间与递归执行的时间相同。我怎样才能避免这种情况

我的输出非常好。我只想了解这种行为的原因以及如何避免

Answer 1

当您在函数完成之前调用自身中的create_schedule函数时，一旦它到达末尾，并且不需要再次调用自己，每个函数都会结束，并在函数末尾点击“After completely solving coming here.”

这意味着每个函数在调用它自己之后，仍然在运行-只是停留在它调用它自己的那一行-直到它们全部完成，这时暂停的函数可以完成它们的任务，打印出您的语句