web 框架本质  -  Web应用本质上就是一个socket服务端，而用户的浏览器就是一个socket客户端。

 HTTP协议

HTTP协议介绍HTTP协议对收发消息的格式要求每个HTTP请求和响应都遵循相同的格式，一个HTTP包含Header和Body两部分，其中Body是可选的。HTTP响应的Header中有一个 Content-Type表明响应的内容格式。它的值如text/html; charset=utf-8。text/html则表示是网页，charset=utf-8则表示编码为utf-8。

socket 服务端 基础版-------------------------import socketsk = socket.socket()sk.bind((‘127.0.0.1‘,8002))sk.listen()while True: conn,addr = sk.accept() data = conn.recv(8096) print(data) conn.send(b‘HTTP/1.1 200 ok\r\nk1: v1\r\n\r\n‘) conn.send(b‘<h1>ok!</h1>‘) conn.close()
----------------------------------
根据不同路径返回不同内容

while True:
 conn,addr = sk.accept()
 data = conn.recv(8096)
 data = data.decode()
 url = data.split()[1]
 conn.send(b‘HTTP/1.1 200 ok\r\nk1: v1\r\n\r\n‘)
 if url == ‘/sx‘:
 conn.send(b‘11‘)
 elif url == ‘/bj‘:
 conn.send(b‘22‘)
 else:
 conn.send(b‘not found!‘)
 conn.close()
-----------------------------------
--def 函数版---

import socket
sk = socket.socket()
sk.bind((‘127.0.0.1‘,8002))
sk.listen()
def sx(url):
 ret = ‘nihao - {}‘.format(url)
 return ret.encode()
def bj(url):
 ret = ‘huairen - {}‘.format(url)
 return ret.encode()
while True:
 conn,addr = sk.accept()
 data = conn.recv(8096)
 data = data.decode()
 url = data.split()[1]
 conn.send(b‘HTTP/1.1 200 ok\r\nk1: v1\r\n\r\n‘)
 if url == ‘/sx‘:
 ret = sx(url)
 elif url == ‘/bj‘:
 ret = bj(url)
 else:
 ret = b‘not found‘
 conn.send(ret)
 conn.close()
-----------------------------------
进阶列表版

import socket
sk = socket.socket()
sk.bind((‘127.0.0.1‘,8002))
sk.listen()
def sx(url):
 ret = ‘nihao - {}‘.format(url)
 return ret.encode()
def bj(url):
 ret = ‘huairen - {}‘.format(url)
 return ret.encode()
# 定义一个地址和函数的对应关系的列表
list1 = [(‘/sx‘,sx),(‘/bj‘,bj)]
while True:
 conn,addr = sk.accept()
 data = conn.recv(8096) # 接收数据
 data = data.decode()
 url = data.split()[1] # 获取url
 conn.send(b‘HTTP/1.1 200 ok\r\nk1: v1\r\n\r\n‘)
 func = None
 for i in list1:
 if url == i[0]:
 func = i[1]
 break
 if func:
 ret = func(url)
 else:
 ret = b‘not found‘ 
 conn.send(ret)
 conn.close()
----返回html网页------------------

def index(url):
 with open(‘index.html‘, ‘rb‘) as f:
 ret = f.read()
 return ret

list1 = [(‘/sx‘,sx),(‘/index‘,index)]
--------返回一个动态页面------------

def timer(url):
 now = time.strftime(‘%Y-%m-%d %H:%M:%S‘,time.localtime())
 with open(‘time.html‘,‘r‘,encoding=‘utf-8‘) as f:
 data = f.read()
 data = data.replace(‘@@time@@‘,now)
 return data.encode(‘utf-8‘)
list1 = [(‘/sx‘,sx),(‘/index‘,index),(‘/timer‘,timer)]

"""根据URL中不同的路径返回不同的内容--函数进阶版返回HTML页面让网页动态起来wsgiref模块版"""--------------------------------------------------from wsgiref.simple_server import make_serverdef index(url): with open(‘index.html‘,‘r‘,encoding=‘utf-8‘) as f: s = f.read() return bytes(s,encoding=‘utf-8‘)def timer(url): import time with open(‘time.html‘,‘r‘,encoding=‘utf-8‘) as f: s = f.read() s = s.replace(‘@@time@@‘,time.strftime("%Y-%m-%d %H:%M:%S")) return bytes(s,encoding=‘utf-8‘)list1 = [(‘/index/‘,index),(‘/time/‘,timer)]def run_server(environ,start_response): #设置http 响应的状态码和头信息 start_response(‘200 OK‘,[(‘Content-Type‘, ‘text/html;charset=utf8‘),]) url = environ[‘PATH_INFO‘] #取到用户输入的url func = None for i in list1: if i[0] == url: func = i[1] break if func: response = func(url) else: response = b‘404 not found!‘ return [response,]if __name__ == ‘__main__‘: httpd = make_server(‘127.0.0.1‘,8888,run_server) print(‘我在8888等你呦...‘) httpd.serve_forever()

------------引用第三方 jinja2----------
from wsgiref.simple_server import make_serverfrom jinja2 import Templatedef index(url): #读取html文件 with open(‘index2.html‘,‘r‘,encoding=‘utf-8‘) as f: data = f.read() temp = Template(data) #生成模板文件 ret = temp.render({‘name‘:‘alex‘,‘hobby_list‘: [‘抽烟‘, ‘喝酒‘, ‘烫头‘]})#把数据填充到模板中 return bytes(ret,encoding=‘utf-8‘)def home(url): with open(‘home.html‘,‘r‘,encoding=‘utf-8‘) as f: s = f.read() return bytes(s,encoding=‘utf-8‘)list1 = [(‘/index/‘,index),(‘/home/‘,home)]def run_server(environ,start_response): #设置http 响应的状态码和头信息 start_response(‘200 OK‘,[(‘Content-Type‘, ‘text/html;charset=utf8‘),]) url = environ[‘PATH_INFO‘] #取到用户输入的url func = None for i in list1: if i[0] == url: func = i[1] break if func: response = func(url) else: response = b‘404 not found!‘ return [response,]if __name__ == ‘__main__‘: httpd = make_server(‘127.0.0.1‘,8888,run_server) print(‘我在8888等你呦...‘) httpd.serve_forever()