self.variable.function()在python中的意思是通过类self variable访问一个方法[closed]

class Node:

    def __init__(self, data):
        self.left = None
        self.right = None
        self.data = data

    def insert(self, data):
        if self.data:


            if data < self.data:
                if self.left is None:
                    self.left = Node(data)
                else:
                    self.left.insert(data)
            elif data > self.data:
                if self.right is None:
                    self.right = Node(data)
                else:
                    self.right.insert(data)
            else:
                self.data = data

    def PrintTree(self):
        if self.left:
            self.left.PrintTree()
        print(self.data),
        if self.right:
            self.right.PrintTree()


if __name__ == "__main__":
    root = Node(12)
    root.insert(6)
    root.insert(14)
    root.insert(3)

    root.PrintTree()

但我仍然想知道在下面几行,他们通过变量调用函数:

self.left.insert(data)

然后:

self.right.insert(data)

以及:

self.left.PrintTree()