51web開發(fā)3_路由功能_exc_路由正則匹配

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目錄

ver1：... 1

ver2，路由字典實(shí)現(xiàn)... 2

ver3，將路由功能封裝成類：... 4

ver4，404處理，webob.exc異常：... 5

ver5，注冊(cè)函數(shù)改造：... 7

路由正則匹配：... 10

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web框架開發(fā)：

route路由：

簡單說，就是路怎么走，按不同的路徑分發(fā)數(shù)據(jù)；

url就是不同資源的路徑，不同的路徑應(yīng)對(duì)應(yīng)不同的應(yīng)用程序來處理；

所以，代碼中應(yīng)增加對(duì)路徑的分析處理；

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不管是靜態(tài)web服務(wù)器，還是動(dòng)態(tài)web服務(wù)器，都需要路徑和資源（或處理程序）的映射，最終返回html的文本；

靜態(tài)web server，解決路徑和文件之間的映射；

動(dòng)態(tài)web server，解決路徑和應(yīng)用程序之間的映射；

所有的web框架都是如此，都有路徑配置；

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路由功能實(shí)現(xiàn)：

例：

增加路由：

/?? #返回歡迎內(nèi)容

/python?? #返回hello python

其它?? #404

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ver1：

例：

@dec.wsgify

def app(request):

??? res = Response()

??? if request.path == '/':

??????? res.body = '<h2>welcome</h2>'.encode()

??? elif request.path == '/python':

??????? res.body = '<h2>hello python</h2>'.encode()

??? else:

??????? res.status_code = 404

??????? res.body = 'Not Found'.encode()

??? return res

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ver2，路由字典實(shí)現(xiàn)

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例：

def index(request):

??? res = Response()

??? res.body = '<h2>welcome</h2>'.encode()

??? return res

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def showpython(request):

??? res = Response()

??? res.body = '<h2>hello python</h2>'.encode()

??? return res

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def notfound(request):

??? res = Response()

??? res.body = '<h2>Not Found</h2>'.encode()

??? return res

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@dec.wsgify

def app(request):

??? if request.path == '/':

??????? return index(request)

??? elif request.path == '/python':

??????? return showpython(request)

??? else:

??????? return notfound(request)

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例：

def index(request):

??? res = Response()

??? res.body = '<h2>welcome</h2>'.encode()

??? return res

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def showpython(request):

??? res = Response()

??? res.body = '<h2>hello python</h2>'.encode()

??? return res

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def notfound(request):

??? res = Response()

??? res.body = '<h2>Not Found</h2>'.encode()

??? return res

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route_table = {

??? '/': index,

??? '/python': showpython

}

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@dec.wsgify

def app(request):

??? return route_table.get(request.path, notfound)(request)

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例：

增加注冊(cè)功能；

def index(request):

??? res = Response()

??? res.body = '<h2>welcome</h2>'.encode()

??? return res

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def showpython(request):

??? res = Response()

??? res.body = '<h2>hello python</h2>'.encode()

??? return res

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def notfound(request):

??? res = Response()

??? res.body = '<h2>Not Found</h2>'.encode()

??? return res

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route_table = {}

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def register(path, handler):

??? route_table[path] = handler

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register('/', index)

register('/python', showpython)

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@dec.wsgify

def app(request):

??? return route_table.get(request.path, notfound)(request)

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ver3，將路由功能封裝成類：

思考如何把哪些函數(shù)放到外面；

好處，封裝在類里的，隨著類中代碼越來越多，方便之后移走，模塊化；

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例：

from webob import Request, Response, dec

from wsgiref.simple_server import make_server

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def index(request):

??? res = Response()

??? res.body = '<h2>welcome</h2>'.encode()

??? return res

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def showpython(request):

??? res = Response()

??? res.body = '<h2>hello python</h2>'.encode()

??? return res

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class Application:

??? def notfound(self, request):

??????? res = Response()

??????? res.body = '<h2>Not Found</h2>'.encode()

??????? return res

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??? ROUTE_TABLE = {}?? #類屬性

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??? @classmethod?? #類方法和普通方法都可，最好用類方法

??? def register(cls, path, handler):

??????? cls.ROUTE_TABLE[path] = handler

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??? @dec.wsgify

??? def __call__(self, request:Request) -> Response:

??????? return self.ROUTE_TABLE.get(request.path, self.notfound)(request)

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Application.register('/', index)

Application.register('/python', showpython)

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if __name__ == '__main__':

??? ip = '127.0.0.1'

??? port = 9999

??? app = Application()

??? # app.register('/', index)?? #實(shí)例也可注冊(cè)，但這樣不好

??? # app.register('/python', showpython)

??? server = make_server(ip, port, app)

??? try:

??????? server.serve_forever()

??? except KeyboardInterrupt:

??????? pass

??? finally:

??????? server.shutdown()

??????? server.server_close()

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ver4，404處理，webob.exc異常：

查看源碼：

class HTTPNotFound(HTTPClientError):?? #繼承順序HTTPClientError-->HTTPError-->WSGIHTTPException-->Response

??? code = 404

??? title = 'Not Found'

??? explanation = ('The resource could not be found.')

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注：

code、title、explanation，頁面展示先是這三個(gè)，再是自定義的body內(nèi)容；

若要覆蓋body，要在Response的__init__()中設(shè)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):

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例：

class Application:

??? # def notfound(self, request):

??? #???? res = Response()

??? #???? res.body = '<h2>Not Found</h2>'.encode()

??? #???? return res

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??? ROUTE_TABLE = {}

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??? @classmethod

??? def register(cls, path, handler):

??????? cls.ROUTE_TABLE[path] = handler

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??? @dec.wsgify

??? def __call__(self, request:Request) -> Response:

??????? try:

??????????? return self.ROUTE_TABLE[request.path](request)

??????? except:

??????????? # return self.notfound(request)

??????????? raise exc.HTTPNotFound('您訪問的頁面被外星人劫持了')?? #所有異常都拋404，即便是內(nèi)部定義的函數(shù)有問題也這樣，沒必要拋5XX之類的錯(cuò)誤，防止別人拿到相關(guān)信息反推服務(wù)器版本之類的，b端不能看到服務(wù)器這邊的異常

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例：

class MyHTTPNotFound(exc.HTTPNotFound):

??? code = 404

??? title = 'nimei'

??? explanation = 'nimeide'

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class Application:

??? # def notfound(self, request):

??? #???? res = Response()

??? #???? res.body = '<h2>Not Found</h2>'.encode()

??? #???? return res

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??? ROUTE_TABLE = {}

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??? @classmethod

??? def register(cls, path, handler):

??????? cls.ROUTE_TABLE[path] = handler

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??? @dec.wsgify

??? def __call__(self, request:Request) -> Response:

??????? try:

????? ??????return self.ROUTE_TABLE[request.path](request)

??????? except:

??????????? # return self.notfound(request)

??????????? # raise exc.MyHTTPNotFound('您訪問的頁面被外星人劫持了')

??????????? raise MyHTTPNotFound()

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ver5，注冊(cè)函數(shù)改造：

到此步，一個(gè)框架的雛形基本完成；

Application()是wsgi app，這個(gè)應(yīng)用程序已變成了一個(gè)路由程序，處理邏輯已移到外面，外面的這部分就是留給程序員要完成的；

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例：

from webob import Request, Response, dec, exc

from wsgiref.simple_server import make_server

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class MyHTTPNotFound(exc.HTTPNotFound):

??? code = 404

??? title = 'nimei'

??? explanation = 'nimeide'

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class Application:

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??? ROUTE_TABLE = {}

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??? @classmethod

??? def register(cls, path):

??????? def wrapper(handler):

??????????? cls.ROUTE_TABLE[path] = handler

??????????? return handler

??????? return wrapper

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??? @dec.wsgify

??? def __call__(self, request:Request) -> Response:

??????? try:

??????????? return self.ROUTE_TABLE[request.path](request)

??????? except:

??????????? # raise exc.MyHTTPNotFound('您訪問的頁面被外星人劫持了')

??????????? raise MyHTTPNotFound()

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# Application.register('/', index)

# Application.register('/python', showpython)

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@Application.register('/')

def index(request):

??? res = Response()

??? res.body = '<h2>welcome</h2>'.encode()

??? return res

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@Application.register('/python')

def showpython(request):

??? res = Response()

??? res.body = '<h2>hello python</h2>'.encode()

??? return res

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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()

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例，簡潔代碼：

from wsgiref.simple_server import make_server

from webob import Request, Response, dec, exc

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class Application:

??? ROUTE_TABLE = {}

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??? @classmethod

??? def register(cls, path):

??????? def wrapper(handler):

??????????? cls.ROUTE_TABLE[path] = handler

??????????? return handler

??????? return wrapper

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??? @dec.wsgify

??? def __call__(self, request:Request) -> Response:

??????? try:

??????????? return self.ROUTE_TABLE[request.path](request)

??????? except:

??????????? raise exc.HTTPNotFound()

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@Application.register('/')

def index(request):

??? res = Response()

??? res.body = '<h2>welcome</h2>'.encode()

??? return res

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@Application.register('/python')

def showpython(request):

??? res = Response()

??? res.body = '<h2>hello python</h2>'.encode()

??? return res

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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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路由正則匹配：

以上的路由實(shí)現(xiàn)，非常死板，用re改造；

注冊(cè)的時(shí)候，存入不再是路徑字符串，而是pattern；

__call__()實(shí)現(xiàn)模式和傳入路徑的比較；

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注：

httpd編譯安裝前要裝pcre；

nginx自身已打包好相關(guān)的正則，所以不依賴第三方庫；

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regex=re.compile(r'PATTERN')?? #編譯正則表達(dá)式；url只一行單選模式即可

regex.match(STRING)?? #必須從頭開始匹配，只匹配一次

regex.search(STRING)?? #只匹配一次

regex.fullmatch(STRING)?? #完全匹配

regex.findall(STRING)?? #從頭開始找，找到所有匹配

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py中分組捕獲：

/(?P<biz>.*)/(?P<url>.*)?? #貪婪

/(?P<biz>.*?)/(?P<url>.*?)?? #非貪婪

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例：

@Application.register('/python$')?? #只匹配/python

@Application.register('^/$')?? #只匹配根，放最后匹配

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例：

from wsgiref.simple_server import make_server

from webob import Request, Response, dec, exc

import re

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class Application:

??? # ROUTE_TABLE = {}

??? ROUTE_TABLE = []?? #[(re.compile(pattern), handler)]，二元組列表；此處用列表或有序字典；用dict不合適，key是路徑模式，不能保證其順序，匹配的時(shí)候應(yīng)是有序的

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??? @classmethod

??? def register(cls, pattern):

??????? def wrapper(handler):

??????????? cls.ROUTE_TABLE.append((re.compile(pattern), handler))?? #注冊(cè)的時(shí)候編譯正則表達(dá)式

??????????? return handler

??????? return wrapper

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??? @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()

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@Application.register('^/python$')?? #有匹配的順序，根放到最后；showpython=Application.register('^/python$')(showpython)

def showpython(request):

??? res = Response()

??? res.body = '<h2>hello python</h2>'.encode()

??? return res

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@Application.register('^/$')

def index(request):

??? res = Response()

??? res.body = '<h2>welcome</h2>'.encode()

??? return res

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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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