在Python中初始化嵌套类 [英] Initialising nested classes in Python

问题描述

假设我要创建一个房屋"类，该类具有自己的某些属性，但还具有一个(嵌套的)居民"类，该类具有一些属性并具有一个强制属性姓".尽管没有任何居民，但房屋实例可能存在.如何创建它，以便我最终可以执行以下操作?

  myhouse = House()residentX = myhouse.resident('Smith') 

当前，我将其设置为嵌套类，但由于初始化嵌套类(此时不一定需要)，我在尝试初始化myhouse时遇到麻烦

  class House:def __init __():self.someattribute =< someattribute>self.resident = self.Resident()班级居民:def __init __(自己，姓):self.surname =姓 

我知道我可以重组代码以不使用嵌套类，然后在代码中将任何居民明确地绑定到房屋.但是，我想在此处使用点符号(myhouse.resident)将居民自动绑定到房屋.

此外，我了解到python中的嵌套类有些皱眉-我愿意就如何以更pythonic的方式进行上述操作提出建议.

解决方案

我将分解 Resident 类，并为 .resident

赞:

  class House:def __init __():self.someattribute =< someattribute>self._resident =无@财产def居民(自己):返回self._resident@ resident.setterdef居民(个人，姓):r =居民(姓)self._resident = r班级居民:def __init __(自己，姓):self.surname =姓 

但是，如果希望 .resident 是可调用的，但又想跟踪房屋的居民，则仍然可以拆分 Resident 类，并使用:

  class House:def __init __():self.someattribute =< someattribute>self.residents = []def居民(个人，姓):'''将居民添加到房屋中'''r =居民(姓)self.residents.append(r)返回r班级居民:def __init __(自己，姓):self.surname =姓 

Let's say I want to create a class 'House' that has some attributes of its own, but also has a (nested?) 'Resident' class which has some attributes and has a mandatory attribute 'surname'. A house instance may exist though without any residents. How can create this so that I can eventually do the following?

myhouse = House()
residentX = myhouse.resident('Smith')

Currently I set this up as a nested class but run into trouble when I try and initialise myhouse given that it is requiring a surname at this point for the nested Resident class (which I don't necessarily have at this point)

class House:
    def __init__(self):
        self.someattribute = <someattribute>
        self.resident = self.Resident()

    class Resident:
        def __init__(self, surname):
            self.surname = surname

I know I can restructure the code to not use nested classes and then explicitly tie any resident to a house in my code. However, I would like to use the dot notation here (myhouse.resident) to automatically tie a resident to a house.

Also, I understand that nested classes in python are somewhat frowned upon - I'm open to suggestions on how to do the above in a more pythonic manner.

解决方案

I would break out the Resident class and use a property/setter for .resident

Like this:

class House:
    def __init__(self):
        self.someattribute = <someattribute>
        self._resident = None

    @property
    def resident(self):
        return self._resident

    @resident.setter
    def resident(self, surname):
        r = Resident(surname)
        self._resident = r

class Resident:
    def __init__(self, surname):
        self.surname = surname

However, if you want .resident to be callable but also want to track the house's residents, you can still break out the Resident class, and use:

class House:
    def __init__(self):
        self.someattribute = <someattribute>
        self.residents = []

    def resident(self, surname):
        '''
        Add a resident to the house
        '''
        r = Resident(surname)
        self.residents.append(r)
        return r

class Resident:
    def __init__(self, surname):
        self.surname = surname

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