Web框架初识
一、Web框架本质—自己实现Web框架
1、所有的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
import socket
sk = socket.socket()
sk.bind(('127.0.0.1', 8888))
sk.listen()
while True:
conn, addr = sk.accept()
data = conn.recv(8192)
conn.send(b'OK')
conn.close()
2、增加HTTP协议响应头
import socket
sk = socket.socket()
sk.bind(('127.0.0.1', 8888))
sk.listen()
while True:
conn, addr = sk.accept()
data = conn.recv(8192)
conn.send(b'HTTP/1.1 200 OK\r\n\r\n')
conn.send(b'OK')
conn.close()
3、根据用户请求不同的URL返回不同的内容
import socket
sk = socket.socket()
sk.bind(('127.0.0.1', 8888))
sk.listen()
# 将不同的页面封装成不同的函数
def index(url):
page = "这是 {} 页面！".format(url)
return bytes(page, encoding="utf8")
def home(url):
page = "这是 {} 页面！".format(url)
return bytes(page, encoding="utf8")
while True:
conn, addr = sk.accept()
data = conn.recv(8192)
# 根据接收用户的信息获取url路径
data = str(data, encoding='utf-8')
data1 = data.split("\r\n")[0]
url = data1.split()[1]
# 根据不同的路径返回不同内容
if url == "/index/":
response = index(url)
elif url == "/home/":
response = home(url)
else:
response = b"404 NOT FOUND"
# 给客户端发送数据
conn.send(b'HTTP/1.1 200 OK\r\nContent-Type: text/html; charset=utf-8\r\n\r\n')
conn.send(response)
conn.close()
4、用反射优化请求不同URL返回不同内容
import socket
sk = socket.socket()
sk.bind(('127.0.0.1', 8888))
sk.listen()
# 将不同的页面封装成不同的函数
def index(url):
page = "这是 {} 页面！".format(url)
return bytes(page, encoding="utf8")
def home(url):
page = "这是 {} 页面！".format(url)
return bytes(page, encoding="utf8")
# 定义一个url和实际要执行的函数的对应关系
url_list = [
("/index/", index),
("/home/", home),
]
while True:
conn, addr = sk.accept()
data = conn.recv(8192)
# 根据接收用户的信息获取url路径
data = str(data, encoding="utf-8")
data1 = data.split("\r\n")[0]
url = data1.split()[1]
# 根据不同的路径返回不同内容
func = None
for i in url_list:
if i[0] == url:
func = i[1]
break
if func:
response = func(url)
else:
response = b"404 NOT FOUND"
# 给客户端发送数据
conn.send(b'HTTP/1.1 200 OK\r\nContent-Type: text/html; charset=utf-8\r\n\r\n')
conn.send(response)
conn.close()
5、返回完整的静态HTML
import socket
sk = socket.socket()
sk.bind(('127.0.0.1', 8888))
sk.listen()
# 将不同的页面封装成不同的函数
def index(url):
with open("index.html", "r", encoding="utf8") as f:
s = f.read()
return bytes(s, encoding="utf8")
def home(url):
with open("home.html", "r", encoding="utf8") as f:
s = f.read()
return bytes(s, encoding="utf8")
# 定义一个url和实际要执行的函数的对应关系
url_list = [
("/index/", index),
("/home/", home),
]
while True:
conn, addr = sk.accept()
data = conn.recv(8192)
# 根据接收用户的信息获取url路径
data = str(data, encoding="utf-8")
data1 = data.split("\r\n")[0]
url = data1.split()[1]
# 根据不同的路径返回不同内容
func = None
for i in url_list:
if i[0] == url:
func = i[1]
break
if func:
response = func(url)
else:
response = b"404 NOT FOUND"
# 给客户端发送数据
conn.send(b'HTTP/1.1 200 OK\r\nContent-Type: text/html; charset=utf-8\r\n\r\n')
conn.send(response)
conn.close()
6、返回动态的HTML，本质上就是HTML内容中利用一些特殊的符号来替换要展示的数据；模板渲染有个现成的工具：jinja2
import time
import socket
sk = socket.socket()
sk.bind(('127.0.0.1', 8888))
sk.listen()
# 将不同的页面封装成不同的函数
def index(url):
with open("index.html", "r", encoding="utf8") as f:
s = f.read()
now = str(time.asctime(time.localtime(time.time())))
s = s.replace("@@oo@@", now)
return bytes(s, encoding="utf8")
def home(url):
with open("home.html", "r", encoding="utf8") as f:
s = f.read()
return bytes(s, encoding="utf8")
# 定义一个url和实际要执行的函数的对应关系
url_list = [
("/index/", index),
("/home/", home),
]
while True:
conn, addr = sk.accept()
data = conn.recv(8192)
# 根据接收用户的信息获取url路径
data = str(data, encoding="utf-8")
data1 = data.split("\r\n")[0]
url = data1.split()[1]
# 根据不同的路径返回不同内容
func = None
for i in url_list:
if i[0] == url:
func = i[1]
break
if func:
response = func(url)
else:
response = b"404 NOT FOUND"
# 给客户端发送数据
conn.send(b'HTTP/1.1 200 OK\r\nContent-Type: text/html; charset=utf-8\r\n\r\n')
conn.send(response)
conn.close()
7、返回动态的HTML，wsgiref版
import time
from wsgiref.simple_server import make_server
# 将不同的页面封装成不同的函数
def index(url):
with open("index.html", "r", encoding="utf8") as f:
s = f.read()
now = str(time.asctime(time.localtime(time.time())))
s = s.replace("@@oo@@", now)
return bytes(s, encoding="utf8")
def home(url):
with open("home.html", "r", encoding="utf8") as f:
s = f.read()
return bytes(s, encoding="utf8")
# 定义一个url和实际要执行的函数的对应关系
url_list = [
("/index/", index),
("/home/", home),
]
def run_server(environ, start_response):
start_response('200 OK', [('Content-Type', 'text/html;charset=utf8'), ]) # 设置HTTP响应的状态码和头信息
url = environ['PATH_INFO'] # 取到用户输入的url
# 根据不同的路径返回不同内容
func = None
for i in url_list:
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("Serving HTTP on port 8888...")
httpd.serve_forever()
8、返回动态的HTML，wsgiref + jinja2 版
import time
import jinja2
from wsgiref.simple_server import make_server
# 将不同的页面封装成不同的函数
def index(url):
with open("index.html", "r", encoding="utf8") as f:
s = f.read()
now = str(time.asctime(time.localtime(time.time())))
s = s.replace("@@oo@@", now)
return bytes(s, encoding="utf8")
def home(url):
with open("home.html", "r", encoding="utf8") as f:
s = f.read()
return bytes(s, encoding="utf8")
def person(url):
with open("person.html", "r", encoding="utf8") as f:
s = f.read()
# 生成一个jinja2的Template（模板）对象
template = jinja2.Template(s)
data = {"name": "Yang", "hobby_list": ["爱好1", "爱好2", "爱好3"]}
# 本质上是完成了字符串的替换
response = template.render(data)
return bytes(response, encoding="utf8")
# 定义一个url和实际要执行的函数的对应关系
url_list = [
("/index/", index),
("/home/", home),
("/person/", person),
]
def run_server(environ, start_response):
start_response('200 OK', [('Content-Type', 'text/html;charset=utf8'), ]) # 设置HTTP响应的状态码和头信息
url = environ['PATH_INFO'] # 取到用户输入的url
# 根据不同的路径返回不同内容
func = None
for i in url_list:
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("Serving HTTP on port 8888...")
httpd.serve_forever()
9、使用pymysql连接数据库
import time
import jinja2
import pymysql
from wsgiref.simple_server import make_server
# 将不同的页面封装成不同的函数
def index(url):
with open("index.html", "r", encoding="utf8") as f:
s = f.read()
now = str(time.asctime(time.localtime(time.time())))
s = s.replace("@@oo@@", now)
return bytes(s, encoding="utf8")
def home(url):
with open("home.html", "r", encoding="utf8") as f:
s = f.read()
return bytes(s, encoding="utf8")
def person(url):
with open("person.html", "r", encoding="utf8") as f:
s = f.read()
# 生成一个jinja2的Template（模板）对象
template = jinja2.Template(s)
conn = pymysql.connect(
host="127.0.0.1",
port=3306,
user="root",
passwd="",
db="userinfo",
charset="utf8"
)
cursor = conn.cursor(cursor=pymysql.cursors.DictCursor)
cursor.execute("SELECT name, hobby FROM user")
user = cursor.fetchone()
cursor.close()
conn.close()
hobby_list = user["hobby"].split()
user["hobby_list"] = hobby_list
# 本质上是完成了字符串的替换
response = template.render(user)
return bytes(response, encoding="utf8")
# 定义一个url和实际要执行的函数的对应关系
url_list = [
("/index/", index),
("/home/", home),
("/person/", person),
]
def run_server(environ, start_response):
start_response('200 OK', [('Content-Type', 'text/html;charset=utf8'), ]) # 设置HTTP响应的状态码和头信息
url = environ['PATH_INFO'] # 取到用户输入的url
# 根据不同的路径返回不同内容
func = None
for i in url_list:
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("Serving HTTP on port 8888...")
httpd.serve_forever()
10、MVC和MTV模式
- Django的MTV模式本质是各组件之间为了保持松耦合关系,Django的MTV分别代表：
- Model(模型)：负责业务对象与数据库的对象(ORM)
- Template(模版)：负责如何把页面展示给用户
- View(视图)：负责业务逻辑，并在适当的时候调用Model和Template
- 此外，Django还有一个url分发器，它的作用是将一个个URL的页面请求分发给不同的view处理，view再调用相应的Model和Template
