Question

我不确定这种语言是否可行，但想象一下：

class Parent(object):
    def __init__(self, number):
        self.variable_to_access = "I want this"
        self.object_list = []
        for i in range(number): self.object_list.append(Object_In_List(i))

class Object_In_List(object):
    def __init__(self): pass

    def my_method(self):
        # How can I access variable_to_access

我已经过度简化了这一点，但我认为Object_In_List可以继承Parent，但Parent将包含许多其他项目，我担心内存使用情况。

我想避免不断传递variable_to_access本身。这实际上是否可以在variable_to_access内访问my_method()？

由于

Answer 1

这是一个稍微复杂的例子，其行为类似于Java内部类

class Parent(object):
    def __init__(self, number):
        self.variable_to_access = "I want this"
        self.object_list = [] for i in range(number): 
            # Pass in a reference to the parent class when constructing our "inner class"
            self.object_list.append(Object_In_List(self, i))

class Object_In_List(object):
    # We need a reference to our parent class
    def __init__(self, parent, i):
        self.parent = parent

    # ... So we can forward attribute lookups on to the parent
    def __getattr__(self, name):
        return getattr(self.parent, name)

    # Now we can treat members of the parent class as if they were our own members (just like Java inner classes)
    def my_method(self):
        # You probably want to do something other than print here
        print(self.variable_to_access)

Answer 2

class Parent(object):
    def __init__(self, number):
        self.variable_to_access = "I want this"
        self.object_list = []
        for i in range(number):
            self.object_list.append(Object_In_List(self.variable_to_access, i))

class Object_In_List(object):
    def __init__(self, parent_var, i):
        self.pv = parent_var

    def my_method(self):
        # How can I access variable_to_access
        # self.pv is what you want

Answer 3

现在似乎唯一存在Object_In_List个Parent对象的地方属于self.object_list属性Parent。如果是这种情况，那么当您访问Object_In_List时，您就在my_method班级，因此您甚至不需要Object_In_List中的Parent。如果这些对象存在于该列表之外，则无论如何都必须传递Parent对象或变量，如其他答案所示。

如果您想要有创意，可以使用{{1}}的类属性。这不会是“变量”，除非你的class属性是一个字典，但是那里有内存。

Python - 如何在列表中的类中访问上述类的变量？

3 个答案: