目录
ver1：...1
ver2，路由字典实现...2
ver3，将路由功能封装成类：...4
ver4，404处理，webob.exc异常：...5
ver5，注册函数改造：...7
路由正则匹配：...10
web框架开发：
route路由：
简单说，就是路怎么走，按不同的路径分发数据；
url就是不同资源的路径，不同的路径应对应不同的应用程序来处理；
所以，代码中应增加对路径的分析处理；
不管是静态web服务器，还是动态web服务器，都需要路径和资源（或处理程序）的映射，最终返回html的文本；
静态web server，解决路径和文件之间的映射；
动态web server，解决路径和应用程序之间的映射；
所有的web框架都是如此，都有路径配置；
路由功能实现：
例：
增加路由：
/ #返回欢迎内容
/python #返回hello python
其它 #404
例：
@dec.wsgify
def app(request):
res = Response()
if request.path == '/':
res.body = '
elif request.path == '/python':
res.body = '
else:
res.status_code = 404
res.body = 'Not Found'.encode()
return res
例：
def index(request):
res = Response()
res.body = '
return res
def showpython(request):
res = Response()
res.body = '
return res
def notfound(request):
res = Response()
res.body = '
return res
@dec.wsgify
def app(request):
if request.path == '/':
return index(request)
elif request.path == '/python':
return showpython(request)
else:
return notfound(request)
例：
def index(request):
res = Response()
res.body = '
return res
def showpython(request):
res = Response()
res.body = '
return res
def notfound(request):
res = Response()
res.body = '
return res
route_table = {
'/': index,
'/python': showpython
}
@dec.wsgify
def app(request):
return route_table.get(request.path, notfound)(request)
例：
增加注册功能；
def index(request):
res = Response()
res.body = '
return res
def showpython(request):
res = Response()
res.body = '
return res
def notfound(request):
res = Response()
res.body = '
return res
route_table = {}
def register(path, handler):
route_table[path] = handler
register('/', index)
register('/python', showpython)
@dec.wsgify
def app(request):
return route_table.get(request.path, notfound)(request)
思考如何把哪些函数放到外面；
好处，封装在类里的，随着类中代码越来越多，方便之后移走，模块化；
例：
from webob import Request, Response, dec
from wsgiref.simple_server import make_server
def index(request):
res = Response()
res.body = '
return res
def showpython(request):
res = Response()
res.body = '
return res
class Application:
def notfound(self, request):
res = Response()
res.body = '
return res
ROUTE_TABLE = {} #类属性
@classmethod #类方法和普通方法都可，最好用类方法
def register(cls, path, handler):
cls.ROUTE_TABLE[path] = handler
@dec.wsgify
def __call__(self, request:Request) -> Response:
return self.ROUTE_TABLE.get(request.path, self.notfound)(request)
Application.register('/', index)
Application.register('/python', showpython)
if __name__ == '__main__':
ip = '127.0.0.1'
port = 9999
app = Application()
# app.register('/', index) #实例也可注册，但这样不好
# app.register('/python', showpython)
server = make_server(ip, port, app)
try:
server.serve_forever()
except KeyboardInterrupt:
pass
finally:
server.shutdown()
server.server_close()
查看源码：
class HTTPNotFound(HTTPClientError): #继承顺序HTTPClientError-->HTTPError-->WSGIHTTPException-->Response
code = 404
title = 'Not Found'
explanation = ('The resource could not be found.')
注：
code、title、explanation，页面展示先是这三个，再是自定义的body内容；
若要覆盖body，要在Response的__init__()中设置；
class Response(object):
def __init__(self, body=None, status=None, headerlist=None, app_iter=None,
content_type=None, conditional_response=None, charset=_marker,
**kw):
例：
class Application:
# def notfound(self, request):
# res = Response()
# res.body = '
# return res
ROUTE_TABLE = {}
@classmethod
def register(cls, path, handler):
cls.ROUTE_TABLE[path] = handler
@dec.wsgify
def __call__(self, request:Request) -> Response:
try:
return self.ROUTE_TABLE[request.path](request)
except:
# return self.notfound(request)
raise exc.HTTPNotFound('您访问的页面被外星人劫持了') #所有异常都抛404，即便是内部定义的函数有问题也这样，没必要抛5XX之类的错误，防止别人拿到相关信息反推服务器版本之类的，b端不能看到服务器这边的异常
例：
class MyHTTPNotFound(exc.HTTPNotFound):
code = 404
title = 'nimei'
explanation = 'nimeide'
class Application:
# def notfound(self, request):
# res = Response()
# res.body = '
# return res
ROUTE_TABLE = {}
@classmethod
def register(cls, path, handler):
cls.ROUTE_TABLE[path] = handler
@dec.wsgify
def __call__(self, request:Request) -> Response:
try:
return self.ROUTE_TABLE[request.path](request)
except:
# return self.notfound(request)
# raise exc.MyHTTPNotFound('您访问的页面被外星人劫持了')
raise MyHTTPNotFound()
到此步，一个框架的雏形基本完成；
Application()是wsgi app，这个应用程序已变成了一个路由程序，处理逻辑已移到外面，外面的这部分就是留给程序员要完成的；
例：
from webob import Request, Response, dec, exc
from wsgiref.simple_server import make_server
class MyHTTPNotFound(exc.HTTPNotFound):
code = 404
title = 'nimei'
explanation = 'nimeide'
class Application:
ROUTE_TABLE = {}
@classmethod
def register(cls, path):
def wrapper(handler):
cls.ROUTE_TABLE[path] = handler
return handler
return wrapper
@dec.wsgify
def __call__(self, request:Request) -> Response:
try:
return self.ROUTE_TABLE[request.path](request)
except:
# raise exc.MyHTTPNotFound('您访问的页面被外星人劫持了')
raise MyHTTPNotFound()
# Application.register('/', index)
# Application.register('/python', showpython)
@Application.register('/')
def index(request):
res = Response()
res.body = '
return res
@Application.register('/python')
def showpython(request):
res = Response()
res.body = '
return res
if __name__ == '__main__':
ip = '127.0.0.1'
port = 9999
app = Application()
# app.register('/', index)
# app.register('/python', showpython)
server = make_server(ip, port, app)
try:
server.serve_forever()
except KeyboardInterrupt:
pass
finally:
server.shutdown()
server.server_close()
例，简洁代码：
from wsgiref.simple_server import make_server
from webob import Request, Response, dec, exc
class Application:
ROUTE_TABLE = {}
@classmethod
def register(cls, path):
def wrapper(handler):
cls.ROUTE_TABLE[path] = handler
return handler
return wrapper
@dec.wsgify
def __call__(self, request:Request) -> Response:
try:
return self.ROUTE_TABLE[request.path](request)
except:
raise exc.HTTPNotFound()
@Application.register('/')
def index(request):
res = Response()
res.body = '
return res
@Application.register('/python')
def showpython(request):
res = Response()
res.body = '
return res
if __name__ == '__main__':
ip = '127.0.0.1'
port = 9999
server = make_server(ip, port, Application())
try:
server.serve_forever()
except:
pass
finally:
server.shutdown()
server.server_close()
以上的路由实现，非常死板，用re改造；
注册的时候，存入不再是路径字符串，而是pattern；
__call__()实现模式和传入路径的比较；
注：
httpd编译安装前要装pcre；
nginx自身已打包好相关的正则，所以不依赖第三方库；
regex=re.compile(r'PATTERN') #编译正则表达式；url只一行单选模式即可
regex.match(STRING) #必须从头开始匹配，只匹配一次
regex.search(STRING) #只匹配一次
regex.fullmatch(STRING) #完全匹配
regex.findall(STRING) #从头开始找，找到所有匹配
py中分组捕获：
/(?P
/(?P
例：
@Application.register('/python$') #只匹配/python
@Application.register('^/$') #只匹配根，放最后匹配
例：
from wsgiref.simple_server import make_server
from webob import Request, Response, dec, exc
import re
class Application:
# ROUTE_TABLE = {}
ROUTE_TABLE = [] #[(re.compile(pattern), handler)]，二元组列表；此处用列表或有序字典；用dict不合适，key是路径模式，不能保证其顺序，匹配的时候应是有序的
@classmethod
def register(cls, pattern):
def wrapper(handler):
cls.ROUTE_TABLE.append((re.compile(pattern), handler)) #注册的时候编译正则表达式
return handler
return wrapper
@dec.wsgify
def __call__(self, request:Request) -> Response:
for regex, handler in self.ROUTE_TABLE:
matcher = regex.search(request.path) #match()、search()均可
if matcher:
return handler(request)
raise exc.HTTPNotFound()
@Application.register('^/python$') #有匹配的顺序，根放到最后；showpython=Application.register('^/python$')(showpython)
def showpython(request):
res = Response()
res.body = '
return res
@Application.register('^/$')
def index(request):
res = Response()
res.body = '
return res
if __name__ == '__main__':
ip = '127.0.0.1'
port = 9999
server = make_server(ip, port, Application())
try:
server.serve_forever()
except:
pass
finally:
server.shutdown()
server.server_close()
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