浅谈 Web框架

一、Web框架本质

  • 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

二、Web框架功能

  • socket收发消息 —— wsgiref（测试）、uwsgi（线上）

  • 根据不同的路径返回不同的字符串

  • 返回动态页面（字符串的替换）—— jinja2

三、Web框架种类

  • django

    • 根据不同的路径返回不同的字符串

    • 返回动态页面（字符串的替换）

  • flask

    • 根据不同的路径返回不同的字符串

  • tornado

    • socket收发消息

    • 根据不同的路径返回不同的字符串

    • 返回动态页面（字符串的替换）

四、自定义web框架

  • 简单示例：socket服务端

    import socket
# 创建一个socket对象
sk = socket.socket()
# 绑定IP和端口
sk.bind(('127.0.0.1', 8000))
# 监听
sk.listen(5)
# 等待连接
while True:
    conn, addr = sk.accept()
    # 接收数据
    data= conn.recv(1024)
    print(data)
    # 返回数据
    conn.send(b'HTTP/1.1 200 OK\r\n\r\n<h1>ok!</h1>')
    # 断开连接
    conn.close()

  • 根据不同路径返回不同的内容（普通版）

    import socket
# 创建一个socket对象
sk = socket.socket()
# 绑定IP和端口
sk.bind(('127.0.0.1', 8000))
# 监听
sk.listen(5)
# 等待连接
while True:
    conn, addr = sk.accept()
    # 接收数据
    data = conn.recv(1024)
    data = data.decode('utf-8')
    url = data.split()[1]
    conn.send(b'HTTP/1.1 200 OK\r\n\r\n')
    if url == '/index/':
        # 返回数据
        conn.send(b'<h1>index!</h1>')
    elif url == '/home/':
        conn.send(b'<h1>home!</h1>')
    else:
        conn.send(b'<h1>404 not found!</h1>')
    # 断开连接
    conn.close()
    普通版
    import socket
# 创建一个socket对象
sk = socket.socket()
# 绑定IP和端口
sk.bind(('127.0.0.1', 8000))
# 监听
sk.listen(5)
# 函数
def index(url):
    ret = '<h1>index!</h1>({})'.format(url)
    return ret.encode('utf-8')
def home(url):
    ret = '<h1>home!</h1>({})'.format(url)
    return ret.encode('utf-8')
# 等待连接
while True:
    conn, addr = sk.accept()
    # 接收数据
    data = conn.recv(1024)
    data = data.decode('utf-8')
    url = data.split()[1]
    conn.send(b'HTTP/1.1 200 OK\r\n\r\n')
    if url == '/index/':
        # 返回数据
        ret = index(url)
    elif url == '/home/':
        ret = home(url)
    else:
        ret = b'<h1>404 not found!</h1>'
    conn.send(ret)
    # 断开连接
    conn.close()
    函数版
    import socket
# 创建一个socket对象
sk = socket.socket()
# 绑定IP和端口
sk.bind(('127.0.0.1', 8000))
# 监听
sk.listen(5)
# 函数
def index(url):
    ret = '<h1>index!</h1>({})'.format(url)
    return ret.encode('utf-8')
def home(url):
    ret = '<h1>home!</h1>({})'.format(url)
    return ret.encode('utf-8')
# 定义一个list1和实际要执行的函数的对应关系 
list1 = [
    ('/index/', index),
    ('/home/', home),
]
# 等待连接
while True:
    conn, addr = sk.accept()
    # 接收数据
    data = conn.recv(1024)
    data = data.decode('utf-8')
    url = data.split()[1]
    conn.send(b'HTTP/1.1 200 OK\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'<h1>404 not found!</h1>'
    conn.send(ret)
    # 断开连接
    conn.close()
    函数进阶版
    import socket
# 创建一个socket对象
sk = socket.socket()
# 绑定IP和端口
sk.bind(('127.0.0.1', 8000))
# 监听
sk.listen(5)
# 函数
def index(url):
    with open('index.html','rb') as f:
        ret = f.read()
    return ret
def home(url):
    ret = '<h1>home!</h1>({})'.format(url)
    return ret.encode('utf-8')
# 定义一个list1和实际要执行的函数的对应关系
list1 = [
    ('/index/', index),
    ('/home/', home),
]
# 等待连接
while True:
    conn, addr = sk.accept()
    # 接收数据
    data = conn.recv(1024)
    data = data.decode('utf-8')
    url = data.split()[1]
    conn.send(b'HTTP/1.1 200 OK\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'<h1>404 not found!</h1>'
    conn.send(ret)
    # 断开连接
    conn.close()
    返回html页面
    import socket
import time
# 创建一个socket对象
sk = socket.socket()
# 绑定IP和端口
sk.bind(('127.0.0.1', 8000))
# 监听
sk.listen(5)
# 函数
def index(url):
    with open('index.html', 'rb') as f:
        ret = f.read()
    return ret
def home(url):
    ret = '<h1>home!</h1>({})'.format(url)
    return ret.encode('utf-8')
def timer(url):
    now = time.strftime('%H:%M:%S')
    with open('time.html','r',encoding='utf-8') as f:
        data = f.read()
    data = data.replace('xxtimexx',now)
​
    return data.encode('utf-8')
# 定义一个list1和实际要执行的函数的对应关系
list1 = [
    ('/index/', index),
    ('/home/', home),
    ('/time/', timer),
]
# 等待连接
while True:
    conn, addr = sk.accept()
    # 接收数据
    data = conn.recv(1024)
    data = data.decode('utf-8')
    url = data.split()[1]
    conn.send(b'HTTP/1.1 200 OK\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'<h1>404 not found!</h1>'
    conn.send(ret)
    # 断开连接
    conn.close()
补充：time.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
    <h1>当前时间是：@@time@@</h1>
</body>
</html>
    返回动态页面

五、wsgiref

  • 常用的WSGI服务器有uWSGI、Gunicorn

    • Python标准库提供的独立WSGI服务器叫wsgiref，Django开发环境用的就是这个模块来做服务器

  • 简单示例：

    """  
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_server     
    
# 将返回不同的内容部分封装成函数   
def index(url):   
    # 读取index.html页面的内容   
    with open("index.html", "r", encoding="utf8") as f:   
        s = f.read()   
    # 返回字节数据   
    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 timer(url):   
    import time   
    with open("time.html", "r", encoding="utf8") as f:   
        s = f.read()   
        s = s.replace('@@time@@', time.strftime("%Y-%m-%d %H:%M:%S"))   
    return bytes(s, encoding="utf8")        
     
# 定义一个url和实际要执行的函数的对应关系   
list1 = [   
    ("/index/", index),   
    ("/home/", home),   
    ("/time/", timer),   
]        
     
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   
    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', 8090, run_server)   
    print("我在8090等你哦...")   
    httpd.serve_forever()
    示例

六、jinja2

  1. 模板渲染现成的工具：jinja2

    • 下载jinja2：pip install jinja2

  2. 示例：

    from wsgiref.simple_server import make_server  
from jinja2 import Template    
  
def index(url):  
    # 读取HTML文件内容  
    with open("index2.html", "r", encoding="utf8") as f:  
        data = f.read()  
        template = Template(data)   # 生成模板文件 
        ret = template.render({'name': 'alex', 'hobby_list': ['抽烟', '喝酒', '烫头']})   # 把数据填充到模板中  
    return bytes(ret, 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  
list1 = [  
    ("/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  
    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', 8090, run_server)  
    print("我在8090等你哦...")  
    httpd.serve_forever() 
    <!DOCTYPE html>
<html lang="zh-CN">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="x-ua-compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <title>Title</title>
</head>
<body>
    <h1>姓名：{{name}}</h1>
    <h1>爱好：</h1>
    <ul>
        {% for hobby in hobby_list %}
            <li>{{hobby}}</li>
        {% endfor %}
    </ul>
</body>
</html>
    index2.html
posted @ 2019-08-09 18:08  林染  阅读(842)  评论(1)  编辑  收藏  举报