class Foo(object):def __init__(self):self.name = "boo"def __getitem__(self, item):print("调用__getitem__了")if item in self.__dict__:return self.__dict__[item]def __setitem__(self, key, value):print("调用__setitem__方法了")self.__dict__[key] = valuedef __delitem__(self, key):print("调用__delitem__")del self.__dict__[key]foo = Foo()
ret = foo["name"]
# print(ret)     # 输出     调用__getitem__了      boo
foo["age"] = 18
# print(foo["age"])   # 输出   调用__setitem__方法了   调用__getitem__了    18
del foo["age"]   #  输出  调用__delitem__

class Foo(object):def __init__(self):self.name = "boo"def __getattr__(self, item):print("调用__getattr__了")def __setattr__(self, key, value):print("调用__setattr__方法了")def __delattr__(self, item):print("调用__delattr__")foo = Foo()
ret = foo.xxx    # 输出     调用__getattr__了
foo.age = 18    # 调用__setattr__方法了
del foo.age   #  输出  调用__delattr__

from functools import partialclass Foo(object):def __init__(self):self.request = "request"self.session = "session"foo = Foo()def func(args):return getattr(foo,args)re_func = partial(func,'request')
se_func = partial(func,'session')print(re_func())

from functools import partialclass HttpRequest(object):def __init__(self):self.method = "GET"self.body = b"name=abc@age=123"class Foo(object):def __init__(self):self.request = HttpRequest()self.session = {"login":True,"is_super":False}foo = Foo()def func(args):return getattr(foo,args)re_func = partial(func,'request')
se_func = partial(func,'session')class LocalProxy(object):def __init__(self,local):self._local = localdef _get_current_object(self):return self._local()def __getitem__(self, item):return getattr(self._get_current_object(),item)request = LocalProxy(re_func)
ret = request._get_current_object().method
print(ret)ret = request['method']
print(ret)session = LocalProxy(se_func)
print(session._get_current_object())

import time
import threadinglocal = threading.local()def func(n):local.val = ntime.sleep(5)print(n)for i in range(10):t = threading.Thread(target=func,args=(i,))t.start()# 结果输出    0--9

import time
import threading
# from threading import current_thread as getcurrent
from greenlet import getcurrentclass Local(object):def __init__(self):object.__setattr__(self,"_storage",{})def __setattr__(self, key, value):# ident = threading.get_ident()ident = getcurrent()   # 定制粒度更细的if ident in self._storage:self._storage[ident][key] = valueelse:self._storage[ident] = {key:value}def __getattr__(self, item):# ident = threading.get_ident()ident = getcurrent()return self._storage[ident][item]local = Local()def func(n):local.val = ntime.sleep(2)print(local.val)for i in range(10):t = threading.Thread(target=func,args=(i,))t.start()

from greenlet import getcurrentclass Local(object):def __init__(self):object.__setattr__(self,"_storage",{})def __setattr__(self, key, value):# ident = threading.get_ident()ident = getcurrent()   # 定制粒度更细的if ident in self._storage:self._storage[ident][key] = valueelse:self._storage[ident] = {key:value}def __getattr__(self, item):# ident = threading.get_ident()ident = getcurrent()return self._storage[ident][item]class LocalStack(object):def __init__(self):self.local = Local()def push(self,item):self.local.stack = []self.local.stack.append(item)def pop(self):return self.local.stack.pop()def top(self):return self.local.stack[-1]_local_stack = LocalStack()
_local_stack.push(55)
print(_local_stack.top())  # 取栈顶元素

from flask import Flaskapp = Flask(__name__)@app.route('/')
def index():return "Hello World"if __name__ == '__main__':app.run()

def application(environ, start_response):start_response('200 OK', [('Content-Type', 'text/html')])return '<h1>Hello, web!</h1>'上面的application()函数就是符合WSGI标准的一个HTTP处理函数，它接收两个参数：environ：一个包含所有HTTP请求信息的dict对象；start_response：一个发送HTTP响应的函数。在application()函数中，调用：start_response('200 OK', [('Content-Type', 'text/html')])

def wsgi_app(self, environ, start_response):ctx = self.request_context(environ)error = Nonetry:try:ctx.push()response = self.full_dispatch_request()except Exception as e:error = eresponse = self.handle_exception(e)except:error = sys.exc_info()[1]raisereturn response(environ, start_response)finally:if self.should_ignore_error(error):error = Nonectx.auto_pop(error)

 def request_context(self, environ):"""Create a :class:`~flask.ctx.RequestContext` representing aWSGI environment. Use a ``with`` block to push the context,which will make :data:`request` point at this request.See :doc:`/reqcontext`.Typically you should not call this from your own code. A requestcontext is automatically pushed by the :meth:`wsgi_app` whenhandling a request. Use :meth:`test_request_context` to createan environment and context instead of this method.:param environ: a WSGI environment"""return RequestContext(self, environ)

def push(self):           top = _request_ctx_stack.topif top is not None and top.preserved:top.pop(top._preserved_exc)# 在执行request_context请求上下文的push方法时，先执行了app_context应用上下文的push方法app_ctx = _app_ctx_stack.topif app_ctx is None or app_ctx.app != self.app:app_ctx = self.app.app_context()app_ctx.push()self._implicit_app_ctx_stack.append(app_ctx)else:self._implicit_app_ctx_stack.append(None)if hasattr(sys, 'exc_clear'):sys.exc_clear()# 然后执行请求上下文对象中LocalStack对象的push方法
        _request_ctx_stack.push(self)# 最后处理sessionif self.session is None:session_interface = self.app.session_interfaceself.session = session_interface.open_session(self.app, self.request)if self.session is None:self.session = session_interface.make_null_session(self.app)

def full_dispatch_request(self):self.try_trigger_before_first_request_functions()try:request_started.send(self)rv = self.preprocess_request()if rv is None:rv = self.dispatch_request()except Exception as e:rv = self.handle_user_exception(e)return self.finalize_request(rv)      

 def process_response(self, response):ctx = _request_ctx_stack.topbp = ctx.request.blueprintfuncs = ctx._after_request_functionsif bp is not None and bp in self.after_request_funcs:funcs = chain(funcs, reversed(self.after_request_funcs[bp]))if None in self.after_request_funcs:funcs = chain(funcs, reversed(self.after_request_funcs[None]))for handler in funcs:response = handler(response)if not self.session_interface.is_null_session(ctx.session):self.session_interface.save_session(self, ctx.session, response)return response

    def save_session(self, app, session, response):domain = self.get_cookie_domain(app)path = self.get_cookie_path(app)# If the session is modified to be empty, remove the cookie.# If the session is empty, return without setting the cookie.if not session:if session.modified:response.delete_cookie(app.session_cookie_name,domain=domain,path=path)return# Add a "Vary: Cookie" header if the session was accessed at all.if session.accessed:response.vary.add('Cookie')if not self.should_set_cookie(app, session):returnhttponly = self.get_cookie_httponly(app)secure = self.get_cookie_secure(app)samesite = self.get_cookie_samesite(app)expires = self.get_expiration_time(app, session)val = self.get_signing_serializer(app).dumps(dict(session))# set_cookie将session写入响应的cookie中
        response.set_cookie(app.session_cookie_name,val,expires=expires,httponly=httponly,domain=domain,path=path,secure=secure,samesite=samesite)

from flask import Flask,request,session,gapp = Flask(__name__)  # type:Flask

@app.before_request
def auth_demo():g.val = 123@app.route('/')
def index():print(g.val)return "Hello World"if __name__ == '__main__':app.run()