本文主要内容：将Web框架和Web服务器结合实现简单的服务器，及相关python知识的了解

0x01 服务器代码（MyWebServer.py）

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# coding:utf-8

import socket
import re
import sys

from multiprocessing import Process
from MyWebFramework import Application

# 设置静态文件根目录
HTML_ROOT_DIR = "./html"

WSGI_PYTHON_DIR = "./wsgipython"


class HTTPServer(object):
    """"""
    def __init__(self, application):
        """构造函数， application指的是框架的app"""
        self.server_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        self.server_socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
        self.app = application

    def start(self):
        self.server_socket.listen(128)
        while True:
            client_socket, client_address = self.server_socket.accept()
            # print("[%s, %s]用户连接上了" % (client_address[0],client_address[1]))
            print("[%s, %s]用户连接上了" % client_address)
            handle_client_process = Process(target=self.handle_client, args=(client_socket,))
            handle_client_process.start()
            client_socket.close()

    def start_response(self, status, headers):
        """
         status = "200 OK"
    headers = [
        ("Content-Type", "text/plain")
    ]
    star
        """
        response_headers = "HTTP/1.1 " + status + "\r\n"
        for header in headers:
            response_headers += "%s: %s\r\n" % header

        self.response_headers = response_headers

    def handle_client(self, client_socket):
        """处理客户端请求"""
        # 获取客户端请求数据
        request_data = client_socket.recv(1024)
        print("request data:", request_data)
        request_lines = request_data.splitlines()
        for line in request_lines:
            print(line)

        # 解析请求报文
        # 'GET / HTTP/1.1'
        request_start_line = request_lines[0]
        # 提取用户请求的文件名
        print("*" * 10)
        print(request_start_line.decode("utf-8"))
        file_name = re.match(r"\w+ +(/[^ ]*) ", request_start_line.decode("utf-8")).group(1)
        method = re.match(r"(\w+) +/[^ ]* ", request_start_line.decode("utf-8")).group(1)

        env = {
            "PATH_INFO": file_name,
            "METHOD": method
        }
        response_body = self.app(env, self.start_response)

        response = self.response_headers + "\r\n" + response_body

        # 向客户端返回响应数据
        client_socket.send(bytes(response, "utf-8"))

        # 关闭客户端连接
        client_socket.close()

    def bind(self, port):
        self.server_socket.bind(("", port))


def main():
    sys.path.insert(1, WSGI_PYTHON_DIR)
    if len(sys.argv) < 2:
        sys.exit("python MyWebServer.py Module:app")
    # python MyWebServer.py  MyWebFrameWork:app
    module_name, app_name = sys.argv[1].split(":")
    # module_name = "MyWebFrameWork"
    # app_name = "app"
    m = __import__(module_name)
    app = getattr(m, app_name)
    http_server = HTTPServer(app)
    # http_server.set_port
    http_server.bind(8000)
    http_server.start()


if __name__ == "__main__":
    main()

1.1 sys.argv

  • sys.argv[]

    一个从程序外部获取参数的桥梁,外部参数不唯一，所以sys.argv以列表形式存储参数；其第一个元素是程序本身，随后才依次是外部给予的参数

  • 简单测试

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#本测试是在jupyter notebook中测试
import sys
sys.argv
['c:\\users\\fishmouse\\appdata\\local\\programs\\python\\python37\\lib\\site-packages\\ipykernel_launcher.py',
 '-f',
 'C:\\Users\\fishmouse\\AppData\\Roaming\\jupyter\\runtime\\kernel-049997d2-f810-4826-9743-6db3b4d2e9ea.json']
  • 本地测试

测试代码

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import sys
b=sys.argv
print(b)

  • 测试结果(第三个输出原因是在测试代码中打印了b[0])

  • Pycharm为当前程序添加（python MyWebServer.py）的参数

0x02 Web框架代码（MyWebFramework.py）

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# coding:utf-8

import time

# from MyWebServer import HTTPServer


# 设置静态文件根目录
HTML_ROOT_DIR = "./html"


class Application(object):
    """框架的核心部分，也就是框架的主题程序，框架是通用的"""
    def __init__(self, urls):
        # 设置路由信息
        self.urls = urls

    def __call__(self, env, start_response):
        path = env.get("PATH_INFO", "/")
        # /static/index.html
        if path.startswith("/static"):
            # 要访问静态文件
            file_name = path[7:]
            # 打开文件，读取内容
            try:
                file = open(HTML_ROOT_DIR + file_name, "rb")
            except IOError:
                # 代表未找到路由信息，404错误
                status = "404 Not Found"
                headers = []
                start_response(status, headers)
                return "not found"
            else:
                file_data = file.read()
                file.close()

                status = "200 OK"
                headers = []
                start_response(status, headers)
                return file_data.decode("utf-8")

        for url, handler in self.urls:
            #("/ctime", show_ctime)
            if path == url:
                return handler(env, start_response)

        # 代表未找到路由信息，404错误
        status = "404 Not Found"
        headers = []
        start_response(status, headers)
        return "not found"


def show_ctime(env, start_response):
    status = "200 OK"
    headers = [
        ("Content-Type", "text/plain")
    ]
    start_response(status, headers)
    return time.ctime()


def say_hello(env, start_response):
    status = "200 OK"
    headers = [
        ("Content-Type", "text/plain")
    ]
    start_response(status, headers)
    return "hello world"

def say_haha(env, start_response):
    status = "200 OK"
    headers = [
        ("Content-Type", "text/plain")
    ]
    start_response(status, headers)
    return "hello big world"

urls = [
            ("/", show_ctime),
            ("/ctime", show_ctime),
            ("/sayhello", say_hello),
            ("/sayhaha", say_haha),
        ]
app = Application(urls)
# if __name__ == "__main__":
#     urls = [
#             ("/", show_ctime),
#             ("/ctime", show_ctime),
#             ("/sayhello", say_hello),
#             ("/sayhaha", say_haha),
#         ]
#     app = Application(urls)
#     http_server = HTTPServer(app)
#     http_server.bind(8000)
#     http_server.start()

2.1 __call__

  • 在Python中，函数其实是一个对象：
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f=abs
f.__name__
'abs'
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f(-123)
123



由于 f 可以被调用，所以，f 被称为可调用对象。
所有的函数都是可调用对象。
一个类实例也可以变成一个可调用对象，只需要实现一个特殊方法__call__()。
  • 我们把 Person 类变成一个可调用对象：
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class Person(object):
    def __init__(self, name, gender):
        self.name = name
        self.gender = gender
    def __call__(self, friend):
        print('My name is %s...' % self.name)
        print ('My friend is %s...' % friend)
  • 可以对 Person 实例直接调用：
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p = Person('Bob', 'male')
p("Tim")
My name is Bob...
My friend is Tim...


单看 p('Tim') 你无法确定 p 是一个函数还是一个类实例，所以，在Python中，函数也是对象，对象和函数的区别并不显著。

测试结果


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本文永久链接是：https://fishni.github.io/2020/04/10/1.6%20python-Web%E6%9C%8D%E5%8A%A1%E5%99%A8%E6%A1%86%E6%9E%B6-%E5%AE%9E%E7%8E%B0/