# Python3中使用urllib.request的请求案例

- Link: https://www.xuepaijie.com/html/skill/devops/792.html
- Published: 2017-02-05T18:18:25+08:00
- Author: Admin

urllib提供了一系列用于操作URL的功能，而urllib的request模块可以非常方便地抓取URL内容，
也就是发送一个GET请求到指定的页面，然后返回HTTP的响应。

基本的网络请求示例

    ```html;
    import urllib.request

    #请求百度网页
    resu = urllib.request.urlopen('https://www.baidu.com', data = None, timeout = 10)
    print(resu.read(300))

    #指定编码请求
    with urllib.request.urlopen('https://www.baidu.com') as resu:
        print(resu.read(300).decode('GBK'))

    #指定编码请求
    f = urllib.request.urlopen('https://www.baidu.com')
    print(f.read(100).decode('utf-8'))
    ```

发送数据请求，CGI程序处理

    ```html;
    import urllib.request

    req = urllib.request.Request(url='http://localhost/cgi-bin/test.cgi', data=b'This data is passed to stdin of the CGI')
    f = urllib.request.urlopen(req)

    print(f.read().decode('utf-8'))
    ```

PUT请求

    ```html;
    import urllib.request

    DATA=b'some data'
    req = urllib.request.Request(url='http://localhost:8080', data=DATA,method='PUT')
    f = urllib.request.urlopen(req)

    print(f.status)
    print(f.reason)
    ```

基本的HTTP验证，登录请求

    ```html;
    import urllib.request

    # Create an OpenerDirector with support for Basic HTTP Authentication...
    auth_handler = urllib.request.HTTPBasicAuthHandler()
    auth_handler.add_password(realm='Application',
                              uri='http://xxx/test.py',
                              user='test',
                              passwd='test')
    opener = urllib.request.build_opener(auth_handler)

    # ...and install it globally so it can be used with urlopen.
    urllib.request.install_opener(opener)
    urllib.request.urlopen('http://www.example.com/login.html')
    ```

支持代理方式验证请求

    ```html;
    proxy_handler = urllib.request.ProxyHandler({'http': 'http://www.example.com/'})
    proxy_auth_handler = urllib.request.ProxyBasicAuthHandler()
    proxy_auth_handler.add_password('aaa', 'bbb', 'username', 'password')

    opener = urllib.request.build_opener(proxy_handler, proxy_auth_handler)

    # This time, rather than install the OpenerDirector, we use it directly:
    opener.open('http://www.example.com/login.html')
    ```

添加 http headers

    ```html;
    import urllib.request

    req = urllib.request.Request('http://www.example.com/')
    req.add_header('Referer', 'http://www.python.org/')
    r = urllib.request.urlopen(req)
    ```

添加 user-agent

    ```html;
    import urllib.request

    opener = urllib.request.build_opener()
    opener.addheaders = [('User-agent', 'Mozilla/5.0')]
    opener.open('http://www.example.com/')
    ```

带参数的GET 请求

    ```html;
    import urllib.request
    import urllib.parse

    params = urllib.parse.urlencode({'a': 1, 'b': 2, 'c': 0})
    f = urllib.request.urlopen("http://xxx/query?%s" % params)

    print(f.read().decode('utf-8'))
    ```

带参数的POST请求

    ```html;
    import urllib.request
    import urllib.parse

    data = urllib.parse.urlencode({'a': 1, 'b': 2, 'c': 0})
    data = data.encode('utf-8')

    request = urllib.request.Request("http://xxx")

    # adding charset parameter to the Content-Type header.
    request.add_header("Content-Type","application/x-www-form-urlencoded;charset=utf-8")
    f = urllib.request.urlopen(request, data)

    print(f.read().decode('utf-8'))
    ```

指定代理方式请求

    ```html;
    import urllib.request

    proxies = {'http': 'http://proxy.example.com:8080/'}
    opener = urllib.request.FancyURLopener(proxies)
    f = opener.open("http://www.python.org")

    f.read().decode('utf-8')
    ```

无添加代理

    ```html;
    import urllib.request

    opener = urllib.request.FancyURLopener({})
    f = opener.open("http://www.python.org/")

    f.read().decode('utf-8')
    ```