python:記一次簡單的模擬flas
- 2020 年 1 月 5 日
- 筆記
最近web伺服器知識，中間懶癌犯了，斷了一兩天後思路有點接不上來，手頭上也有其他事情要做，先簡單的總結下學習進度，很多重要的功能都沒跑通，目前flask只是簡單實現路由分顯示不同的結果，cgi可以根據不同的靜態資源或者py腳本文件路徑顯示不同的結果。目前來說文章亮點就是解耦做的還行，有一定的可擴展性
簡單的仿flask實現路由分發
from wsgiref.simple_server import make_server '''' WSGI規定： 1. 應用程式需要是一個可調用的對象 2. 可調用對象接收兩個參數 3.可調用對象要返回一個值，這個值是可迭代的。 具體參考附錄一，pep-0333標準 ''' class SimServer(object): def __init__(self): self.url_map = {} def __call__(self, environ, start_response): status = u'200 OK' response_headers = [('Content-type', 'text/plain')] start_response(status, response_headers) data=self.dispatch_request(environ) return [data.encode('utf-8'),] def run(self, ip=None, host=None): if not ip: ip = '' if not host: host = 8080 httpd = make_server(ip, host, self) httpd.serve_forever() #路由裝飾器 def route(self, rule): def decorator(f): self.url_map[rule.lstrip('/')] = f return f return decorator #路由的分發 def dispatch_request(self, request): print(request) path = request.get('PATH_INFO', '').lstrip('/') print(path) return self.url_map[path]() # 從url_map中找到對應的處理函數，並調用 #創建一個app app=SimServer() @app.route('/index') def index(): return 'hello world' @app.route('/login') def login(): return 'please login' if __name__=="__main__": app.run() if __name__=="__main__": app.run()
CGI web伺服器，靜態資源的轉發
handler.py
import os import subprocess class BaseHandler(object): '''Parent for case handlers.''' def handle_file(self, handler, full_path): try : with open(full_path, 'rb') as reader: content = reader.read() handler.send_content(content) except IOError as msg: msg = "'{0}' cannot be read: {1}".format(full_path, msg) handler.handle_error(msg) def index_path(self, handler): return os.path.join(handler.full_path, 'index.html') def test(self, handler): assert False, 'Not implemented.' def act(self, handler): assert False, 'Not implemented.' #處理首頁 class Case_directory_idnex_file(BaseHandler): def test(self, handler): return (os.path.isdir(handler.full_path) and os.path.isfile(self.index_path(handler))) def act(self, handler): self.handle_file(handler, self.index_path(handler)) #處理普通html文件 class Case_existing_file(BaseHandler): def test(self, handler): return os.path.isfile((handler.full_path)) def act(self, handler): self.handle_file(handler,handler.full_path) #處理python腳本 class Case_cgi_file(BaseHandler): def run_cgi(self, handler): print('dfs') print(handler.full_path) data=subprocess.getoutput(['python',handler.full_path]) print('data={}'.format(data)) #python3默認使用unicode，需要encode('utf-8') return handler.send_content(data.encode('utf-8')) def test(self,handler): return os.path.isfile(handler.full_path) and handler.full_path.endswith('.py') def act(self,handler): self.run_cgi(handler)
requestHandler.py
from http.server import BaseHTTPRequestHandler,HTTPServer import os from simpleServer.handler import * class RequestHandler(BaseHTTPRequestHandler): Cases = [Case_cgi_file(),Case_directory_idnex_file(),Case_existing_file() ,] # How to display an error. Error_Page = """ <html> <body> <h1>Error accessing {path}</h1> <p>{msg}</p> </body> </html> """ # Classify and handle request. def do_GET(self): try: # 使用join會有問題，目前還沒搞清楚+可以，join會有問題 self.full_path = os.getcwd()+self.path # Figure out how to handle it. print('cases{}'.format(self.Cases)) for case in self.Cases: if case.test(self): case.act(self) break # 處理異常 except Exception as msg: print(msg) self.handle_error(msg) # Handle unknown objects. def handle_error(self, msg): content = self.Error_Page.format(path=self.path, msg=msg) self.send_content(content.encode('utf-8'), 404) # Send actual content. def send_content(self, content, status=200): self.send_response(status) self.send_header("Content-type", "text/html") self.send_header("Content-Length", str(len(content))) self.end_headers() self.wfile.write(content) if __name__=="__main__": severAddress=('',8000) server=HTTPServer(severAddress,RequestHandler) server.serve_forever()
參考附錄
1, pyton：pep-0333 2, flask作者部落格文章：getting-started-with-wsgi 3, 自己寫一個 wsgi 伺服器運行 Django 、Tornado 等框架應用 4, 500L:a-simple-web-server 5, python wsgi簡介 6, 從零開始搭建論壇（二）：Web伺服器網關介面 7, python的 WSGI 簡介 8，本文github源碼
