request为什么可以调用method,sessiion又是如何能获取数据，源码解析

DATA = {
    'request':{
        'method':"GET",
        'form':{}
    },
    'session':{
        'user':'alex',
        'age':"19"
    }
}

class LocalProxy(object):
    def __init__(self,key):
        self.key = key
    def get_dict(self):
        return DATA[self.key]

    def __str__(self):
        return 'asdf'

    def __getattr__(self, item):
        data_dict = self.get_dict()
        return data_dict[item]

    def __getitem__(self, item):
        data_dict = self.get_dict()
        return data_dict[item]

    def __add__(self, other):
        return other + 1

request = LocalProxy('request')
session = LocalProxy('session')