1、web框架介绍
Web框架(Web framework)是一种开发框架,用来支持动态网站、网络应用和网络服务的开发。这大多数的web框架提供了一套开发和部署网站的方式,也为web行为提供了一套通用的方法。web框架已经实现了很多功能,开发人员使用框架提供的方法并且完成自己的业务逻辑,就能快速开发web应用了。浏览器和服务器的是基于HTTP协议进行通信的。也可以说web框架就是在以上十几行代码基础张扩展出来的,有很多简单方便使用的方法,大大提高了开发的效率。
2、实现简单的web框架
基于socket写一个web应用
第一版本
通过HTTP协议传送过来的信息返回页面
import socket server = socket.socket() server.bind((‘127.0.0.1‘,8000)) server.listen(5) while True: conn,addr = server.accept() while True: data = conn.recv(1024) ‘‘‘ ***data*** b‘GET /index/ HTTP/1.1\r\n Host: 127.0.0.1:8000\r\n Connection: keep-alive\r\n Upgrade-Insecure-Requests: 1\r\n User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.131 Safari/537.36\r\n Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3\r\n Accept-Encoding: gzip, deflate, br\r\n Accept-Language: zh-CN,zh;q=0.9,und;q=0.8,en;q=0.7\r\n Cookie: csrftoken=kzAhOkqkoPdnQuOxI7AQTa8aOmT7g6ebPiwrI0jpQ8m04NmYLkzkFvDtD8febu41; Hm_lvt_080836300300be57b7f34f4b3e97d911=1559726342,1559732417\r\n\r\n‘ ‘‘‘ conn.send(b‘HTTP/1.1 200 OK\r\n\r\n‘) ‘‘‘ 页面显示Hello 必须遵守http协议返回一个响应头 ‘‘‘ current_path = data.decode(‘utf-8‘).split(‘\r\n‘)[0].split(‘ ‘)[1] ‘‘‘ /index/ ‘‘‘ if current_path == ‘/index/‘: with open(‘index.html‘, ‘rb‘) as f: conn.send(f.read()) else: conn.send(b‘404‘) conn.close()
第二版本
根据HTTP传送过来的信息返回相应的页面,通过列表保存信息模拟django中的urls,通过函数返回数据模拟django中views
import socket server = socket.socket() server.bind((‘127.0.0.1‘, 8000)) server.listen(5) def index(): return ‘index‘ def login(): return ‘login‘ def error(): return ‘404‘ urls = [ (‘/index/‘, index), (‘/login/‘, login) ] while True: conn, addr = server.accept() while True: data = conn.recv(1024) ‘‘‘ ***data*** b‘GET /index/ HTTP/1.1\r\n Host: 127.0.0.1:8000\r\n Connection: keep-alive\r\n Upgrade-Insecure-Requests: 1\r\n User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.131 Safari/537.36\r\n Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3\r\n Accept-Encoding: gzip, deflate, br\r\n Accept-Language: zh-CN,zh;q=0.9,und;q=0.8,en;q=0.7\r\n Cookie: csrftoken=kzAhOkqkoPdnQuOxI7AQTa8aOmT7g6ebPiwrI0jpQ8m04NmYLkzkFvDtD8febu41; Hm_lvt_080836300300be57b7f34f4b3e97d911=1559726342,1559732417\r\n\r\n‘ ‘‘‘ conn.send(b‘HTTP/1.1 200 OK\r\n\r\n‘) ‘‘‘ 页面显示Hello 必须遵守http协议返回一个响应头 ‘‘‘ current_path = data.decode(‘utf-8‘).split(‘\r\n‘)[0].split(‘ ‘)[1] ‘‘‘ /index/ ‘‘‘ res = None for url in urls: if url[0] == current_path: res = url[1]() break else: res = error() conn.send(res.encode(‘utf-8‘))
第三版
将其拆分成start.py urls.py views.py
import socket import urls server = socket.socket() server.bind((‘127.0.0.1‘, 8000)) server.listen(5) def error(): return ‘404‘ while True: conn, addr = server.accept() while True: data = conn.recv(1024) ‘‘‘ ***data*** b‘GET /index/ HTTP/1.1\r\n Host: 127.0.0.1:8000\r\n Connection: keep-alive\r\n Upgrade-Insecure-Requests: 1\r\n User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.131 Safari/537.36\r\n Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3\r\n Accept-Encoding: gzip, deflate, br\r\n Accept-Language: zh-CN,zh;q=0.9,und;q=0.8,en;q=0.7\r\n Cookie: csrftoken=kzAhOkqkoPdnQuOxI7AQTa8aOmT7g6ebPiwrI0jpQ8m04NmYLkzkFvDtD8febu41; Hm_lvt_080836300300be57b7f34f4b3e97d911=1559726342,1559732417\r\n\r\n‘ ‘‘‘ conn.send(b‘HTTP/1.1 200 OK\r\n\r\n‘) ‘‘‘ 页面显示Hello 必须遵守http协议返回一个响应头 ‘‘‘ current_path = data.decode(‘utf-8‘).split(‘\r\n‘)[0].split(‘ ‘)[1] ‘‘‘ /index/ ‘‘‘ res = None for url in urls.urls: if url[0] == current_path: res = url[1]() break else: res = error() conn.send(res.encode(‘utf-8‘))
import views urls = [ (‘/index/‘, views.index), (‘/login/‘, views.login) ]
def index(): return ‘index‘ def login(): return ‘login‘
高级版
使用wsgiref.simple_server的make_server配置web应用
from wsgiref.simple_server import make_server from urls import * def run(env, response): ‘‘‘ :param env: 请求相关的信息,一个处理好的字符串 :param response: 响应相关信息 :return: ‘‘‘ response(‘200 OK‘, [(‘username‘, ‘jason‘), (‘password‘, ‘123‘)]) # 固定写法 后面列表里面一个个元祖会以响应头kv键值对的形式返回给客户端 current_path = env.get(‘PATH_INFO‘) func = None for url in urls: if current_path == url[0]: func = url[1] break if func: res = func(env) else: res = error(env) return [res.encode(‘utf-8‘)] if __name__ == ‘__main__‘: server = make_server(‘127.0.0.1‘, 8080, run) server.serve_forever()
def index(env): return ‘index‘ def login(env): return ‘login‘ def error(env): return ‘404‘
from views import * urls = [ (‘/index/‘, index), (‘/login/‘, login) ]
终极版
使用jinja2对模板进行替换,对数据库进行连接
from wsgiref.simple_server import make_server from urls import * def run(env, response): ‘‘‘ :param env: 请求相关的信息,一个处理好的字符串 :param response: 响应相关信息 :return: ‘‘‘ response(‘200 OK‘, [(‘username‘, ‘jason‘), (‘password‘, ‘123‘)]) # 固定写法 后面列表里面一个个元祖会以响应头kv键值对的形式返回给客户端 current_path = env.get(‘PATH_INFO‘) func = None for url in urls: if current_path == url[0]: func = url[1] break if func: res = func(env) else: res = error(env) return [res.encode(‘utf-8‘)] if __name__ == ‘__main__‘: server = make_server(‘127.0.0.1‘, 8080, run) server.serve_forever()
import time from jinja2 import Template import pymysql def index(env): return ‘index‘ def login(env): return ‘login‘ def get_time(env): # 先获取当前时间 current_time = time.strftime(‘%Y-%m-%d %X‘) # 打开html文件读取内容返回给客户端 with open(r‘templates/get_time.html‘, ‘r‘, encoding=‘utf-8‘) as f: data = f.read() # 因为是以r模式打开的文件,所有获取到的内容就是一堆字符串 res = data.replace(‘@@[email protected]@‘, current_time) # 字符串的替换 return res def get_user(env): with open(r‘templates/get_user.html‘, ‘r‘, encoding=‘utf-8‘) as f: data = f.read() tmp = Template(data) # 将字典传递给前端页面 前端通过变量名user_dic就可以获取到该字典 return tmp.render(user_dic={‘name‘: "jason", ‘password‘: ‘123‘}) def get_db(env): # 连接数据库 获取数据 渲染到前端页面 conn = pymysql.connect( host=‘127.0.0.1‘, port=3306, user=‘root‘, password=‘123‘, database=‘blog‘, charset=‘utf8‘, autocommit=True ) cursor = conn.cursor(pymysql.cursors.DictCursor) cursor.execute(‘select * from userinfo‘) user_dict = cursor.fetchall() # [{},{},{},{}] with open(r‘templates/get_db.html‘, ‘r‘, encoding=‘utf-8‘) as f: data = f.read() tmp = Template(data) return tmp.render(user_dict=user_dict) def error(env): return ‘404 error‘
from views import * urls = [ (‘/index‘,index), (‘/login‘,login), (‘/get_time‘,get_time), (‘/get_user‘,get_user), (‘/get_db‘,get_db), ]
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>Title</title> </head> <body> @@[email protected]@ </body> </html>
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>Title</title> </head> <body> <p>{{ user_dic }}</p> <p>{{ user_dic.name }}</p> <p>{{ user_dic[‘password‘] }}</p> <p>{{ user_dic.get(‘name‘) }}</p> </body> </html>
原文地址:https://www.cnblogs.com/yuyafeng/p/10981836.html
时间: 2024-10-14 00:52:28