Python Learning-writing a simple web framework (ii)

In the previous log has been discussed and implemented according to the application of the URL, after I read the official document BOTTLE.PY, according to the design of bottle rewrite again, mainly for reference to the design of Daniel's ideas.

A simple example of a bottle.py

Take a look at how bottle is used, and the code comes from http://www.bottlepy.org/docs/0.12/index.html:

 from Import route, run, Template@route ('/hello/<name>') def index (name):     return template ('<b>hello {{name}}</b>! ', name=name) run (host='localhost', port=8080)

Obviously, the bottle is routed using an adorner. Based on the design of bottle, I will write a simple framework.

Python decorator

An adorner, as the name implies, wraps a function. Dynamically adds functionality to a function without changing the function. No more details are being explored here.

The approximate framework

According to the definition of WSGI, a WSGI application must be callable. So here's an approximate framework for a WSGI application:

Class Wsgiapp (object):    def __init__ (self):        pass    def route (Self,path=none):        pass        def __call__ ( Self,environ,start_response):        return Self.wsgi (environ,start_response)    def wsgi (Self,environ,start_ Response):        Pass

Among them, the route method is to save Url->target. Here for convenience, save the Url->target in the dictionary:

    def Route (self,path=None):        def  Decorator (func):            = func             return func         return Decorator

Here return func comment out also can, ask God to explain AH!!

Then there are each method that implements Wsgiapp:

 classWsgiapp (object):def __init__(self): self.routes= {}    defRoute (self,path=None):defDecorator (func): Self.routes[path]=funcreturnfuncreturnDecoratordef __call__(self,environ,start_response):Print 'Pager'        returnSelf.wsgi (environ,start_response)defWsgi (self,environ,start_response): Path= environ['Path_info']        PrintPathifPathinchSelf.routes:status='OK'response_headers= [('Content-type','Text/plain')] Start_response (status,response_headers)PrintSelf.routes[path] ()returnSelf.routes[path] ()Else: Status='404 Not Found'response_headers= [('Content-type','Text/plain')] Start_response (status,response_headers)return '404 Not found!'app=Wsgiapp () @app. Route ('/')defindex ():return['This is index'] @app. Route ('/hello')defHello ():return['Hello'] fromWsgiref.simple_serverImportmake_serverhttpd= Make_server ("', 8000, App)Print 'start ....'Httpd.serve_forever ()

In this way, the prototype of a simple web framework is implemented, and if you add a regular expression to the path in the adorner, you can easily deal with the URL. The next log is to join the template engine jinja2.

Python Learning-writing a simple web framework (ii)