• requests、bs4


    基于http协议:
        - 轮询,定时每秒刷新一次
        - 长轮询,hang住请求(Web微信,WebQQ)
                        - 无消息,超时之后断开,客户端立即发送请求;
                        - 有消息,立即返回
        建立长链接,基于html5                
        - WebSocket:魔法字符串(MagicString)

    requests

    Python标准库中提供了:urllib、urllib2、httplib等模块以供Http请求,但是,它的 API 太渣了。它是为另一个时代、另一个互联网所创建的。它需要巨量的工作,甚至包括各种方法覆盖,来完成最简单的任务。

    Requests 是使用 Apache2 Licensed 许可证的 基于Python开发的HTTP 库,其在Python内置模块的基础上进行了高度的封装,从而使得Pythoner进行网络请求时,变得美好了许多,使用Requests可以轻而易举的完成浏览器可有的任何操作。

    import socket
    
    
    def handle_request(client):
        buf = client.recv(1024)
        client.send(b"HTTP/1.1 302 OK
    location:http://www.baidu.com
    
    ")
        # 重定向location:http://www.baidu.com
        client.send(b"Hello, Seven")
    
    
    def main():
        sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        sock.bind(('localhost', 8000))
        sock.listen(5)
    
        while True:
            connection, address = sock.accept()
            handle_request(connection)
            connection.close()
    
    
    if __name__ == '__main__':
        main()
    web重定向

    1、GET请求

    # 1、无参数实例
    import requests
    ret = requests.get('https://github.com/timeline.json')
    print ret.url
    print ret.text  
    
    # 2、有参数实例
    import requests
    payload = {'key1': 'value1', 'key2': 'value2'}
    ret = requests.get("http://httpbin.org/get", params=payload)  
    
    print ret.url
    print ret.text

    2、POST请求

    # 1、基本POST实例
    import requests 
    payload = {'key1': 'value1', 'key2': 'value2'}
    ret = requests.post("http://httpbin.org/post", data=payload)
    print ret.text
      
    
    # 2、发送请求头和数据实例
    import requests
    import json
    url = 'https://api.github.com/some/endpoint'
    payload = {'some': 'data'}
    headers = {'content-type': 'application/json'}
    ret = requests.post(url, data=json.dumps(payload), headers=headers)  
    
    print ret.text
    print ret.cookies

    3、其他请求

    requests.get(url, params=None, **kwargs)
    requests.post(url, data=None, json=None, **kwargs)
    requests.put(url, data=None, **kwargs)
    requests.head(url, **kwargs)
    requests.delete(url, **kwargs)
    requests.patch(url, data=None, **kwargs)
    requests.options(url, **kwargs)
      
    
    # 以上方法均是在此方法的基础上构建
    requests.request(method, url, **kwargs)

    注意: 请求头
    requests.post(url='',data={}) 默认这个请求头  application/x-www-form-urlencoded;
    requests.post(url='',data={},headers={'content-type': 'application/json'})   # 这个请求只能request.body去拿
    requests.post(url='',json={})  默认请求头:{'content-type': 'application/json'}

    4、更多参数

    def request(method, url, **kwargs):
        """Constructs and sends a :class:`Request <Request>`.
    
        :param method: method for the new :class:`Request` object.
        :param url: URL for the new :class:`Request` object.    
        :param params: (optional) Dictionary or bytes to be sent in the query string for the :class:`Request`.
        # get 传递的参数
        :param data: (optional) Dictionary, bytes, or file-like object to send in the body of the :class:`Request`.
        :param json: (optional) json data to send in the body of the :class:`Request`.
        :param headers: (optional) Dictionary of HTTP Headers to send with the :class:`Request`.
        :param cookies: (optional) Dict or CookieJar object to send with the :class:`Request`.
        :param files: (optional) Dictionary of ``'name': file-like-objects`` (or ``{'name': file-tuple}``) for multipart encoding upload.
            # 文件
            ``file-tuple`` can be a 2-tuple ``('filename', fileobj)``, 3-tuple ``('filename', fileobj, 'content_type')``
            or a 4-tuple ``('filename', fileobj, 'content_type', custom_headers)``, where ``'content-type'`` is a string
            defining the content type of the given file and ``custom_headers`` a dict-like object containing additional headers
            to add for the file.
        :param auth: (optional) Auth tuple to enable Basic/Digest/Custom HTTP Auth.
        # 定制请求头
        def param_auth():
            from requests.auth import HTTPBasicAuth, HTTPDigestAuth
            ret = requests.get('https://api.github.com/user', auth=HTTPBasicAuth('wupeiqi', 'sdfasdfasdf'))
            print(ret.text)
    
        :param timeout: (optional) How long to wait for the server to send data
        # 超时时间,请求超时有两个阶段,请求超时,
            before giving up, as a float, or a :ref:`(connect timeout, read
            timeout) <timeouts>` tuple.
        :type timeout: float or tuple   
        # 如果返回一个数,就是连接的超时时间,返回元组,第一个就是连接的超时时间,第二个是等待的超时时间
        :param allow_redirects: (optional) Boolean. Set to True if POST/PUT/DELETE redirect following is allowed.
        # 是否允许重定向,如果为true则重定向
            requests = requests.post('http://www.baidu.com',allow_redirects=true)
            print(requests.text)
        :type allow_redirects: bool    
        :param proxies: (optional) Dictionary mapping protocol to the URL of the proxy.
        # 代理ip
        def param_proxies():
            proxies = {
            "http": "61.172.249.96:80",  # 代理Ip
            "https": "http://61.185.219.126:3128",
            }
    
            # proxies = {'http://10.20.1.128': 'http://10.10.1.10:5323'}
    
            ret = requests.get("http://www.proxy360.cn/Proxy", proxies=proxies)
            print(ret.headers)
            
            # from requests.auth import HTTPProxyAuth
            #
            # proxyDict = {
            # 'http': '77.75.105.165',
            # 'https': '77.75.105.165'
            # }
            # auth = HTTPProxyAuth('username', 'mypassword')   # 发送代理的账户和密码
            #
            # r = requests.get("http://www.google.com", proxies=proxyDict, auth=auth)
            # print(r.text)
    
    
        :param verify: (optional) whether the SSL cert will be verified. A CA_BUNDLE path can also be provided. Defaults to ``True``.
        # 带不带证书访问
        :param cert: (optional) if String, path to ssl client cert file (.pem). If Tuple, ('cert', 'key') pair.
        equests.get('http://127.0.0.1:8000/test/', verify = True,cert='证书名.pem')
        :param stream: (optional) if ``False``, the response content will be immediately downloaded.
        # 一点一点取传输回来的数据
        def param_stream():
            ret = requests.get('http://127.0.0.1:8000/test/', stream=True)
            print(ret.content)
            ret.close()
    
            # from contextlib import closing  # 自动关闭上下文
            # with closing(requests.get('http://httpbin.org/get', stream=True)) as r:
            # # 在此处理响应。
            # for i in r.iter_content():# 一点一点取传输回来的数据
            #     print(i)  
        :return: :class:`Response <Response>` object
        :rtype: requests.Response
    
        Usage::
    
          >>> import requests
          >>> req = requests.request('GET', 'http://httpbin.org/get')
          <Response [200]>
        """
    更多参数
    def param_method_url():
        # requests.request(method='get', url='http://127.0.0.1:8000/test/')
        # requests.request(method='post', url='http://127.0.0.1:8000/test/')
        pass
    
    
    def param_param():
        # - 可以是字典
        # - 可以是字符串
        # - 可以是字节(ascii编码以内)
    
        # requests.request(method='get',
        # url='http://127.0.0.1:8000/test/',
        # params={'k1': 'v1', 'k2': '水电费'})
    
        # requests.request(method='get',
        # url='http://127.0.0.1:8000/test/',
        # params="k1=v1&k2=水电费&k3=v3&k3=vv3")
    
        # requests.request(method='get',
        # url='http://127.0.0.1:8000/test/',
        # params=bytes("k1=v1&k2=k2&k3=v3&k3=vv3", encoding='utf8'))
    
        # 错误
        # requests.request(method='get',
        # url='http://127.0.0.1:8000/test/',
        # params=bytes("k1=v1&k2=水电费&k3=v3&k3=vv3", encoding='utf8'))
        pass
    
    
    def param_data():
        # 可以是字典
        # 可以是字符串
        # 可以是字节
        # 可以是文件对象
    
        # requests.request(method='POST',
        # url='http://127.0.0.1:8000/test/',
        # data={'k1': 'v1', 'k2': '水电费'})
    
        # requests.request(method='POST',
        # url='http://127.0.0.1:8000/test/',
        # data="k1=v1; k2=v2; k3=v3; k3=v4"
        # )
    
        # requests.request(method='POST',
        # url='http://127.0.0.1:8000/test/',
        # data="k1=v1;k2=v2;k3=v3;k3=v4",
        # headers={'Content-Type': 'application/x-www-form-urlencoded'}
        # )
    
        # requests.request(method='POST',
        # url='http://127.0.0.1:8000/test/',
        # data=open('data_file.py', mode='r', encoding='utf-8'), # 文件内容是:k1=v1;k2=v2;k3=v3;k3=v4
        # headers={'Content-Type': 'application/x-www-form-urlencoded'}
        # )
        pass
    
    
    def param_json():
        # 将json中对应的数据进行序列化成一个字符串,json.dumps(...)
        # 然后发送到服务器端的body中,并且Content-Type是 {'Content-Type': 'application/json'}
        requests.request(method='POST',
                         url='http://127.0.0.1:8000/test/',
                         json={'k1': 'v1', 'k2': '水电费'})
    
    
    def param_headers():
        # 发送请求头到服务器端
        requests.request(method='POST',
                         url='http://127.0.0.1:8000/test/',
                         json={'k1': 'v1', 'k2': '水电费'},
                         headers={'Content-Type': 'application/x-www-form-urlencoded'}
                         )
    
    
    def param_cookies():
        # 发送Cookie到服务器端
        requests.request(method='POST',
                         url='http://127.0.0.1:8000/test/',
                         data={'k1': 'v1', 'k2': 'v2'},
                         cookies={'cook1': 'value1'},
                         )
        # 也可以使用CookieJar(字典形式就是在此基础上封装)
        from http.cookiejar import CookieJar
        from http.cookiejar import Cookie
    
        obj = CookieJar()
        obj.set_cookie(Cookie(version=0, name='c1', value='v1', port=None, domain='', path='/', secure=False, expires=None,
                              discard=True, comment=None, comment_url=None, rest={'HttpOnly': None}, rfc2109=False,
                              port_specified=False, domain_specified=False, domain_initial_dot=False, path_specified=False)
                       )
        requests.request(method='POST',
                         url='http://127.0.0.1:8000/test/',
                         data={'k1': 'v1', 'k2': 'v2'},
                         cookies=obj)
    
    
    def param_files():
        # 发送文件
        # file_dict = {
        # 'f1': open('readme', 'rb')
        # }
        # requests.request(method='POST',
        # url='http://127.0.0.1:8000/test/',
        # files=file_dict)
    
        # 发送文件,定制文件名
        # file_dict = {
        # 'f1': ('test.txt', open('readme', 'rb'))
        # }
        # requests.request(method='POST',
        # url='http://127.0.0.1:8000/test/',
        # files=file_dict)
    
        # 发送文件,定制文件名
        # file_dict = {
        # 'f1': ('test.txt', "hahsfaksfa9kasdjflaksdjf")
        # }
        # requests.request(method='POST',
        # url='http://127.0.0.1:8000/test/',
        # files=file_dict)
    
        # 发送文件,定制文件名
        # file_dict = {
        #     'f1': ('test.txt', "hahsfaksfa9kasdjflaksdjf", 'application/text', {'k1': '0'})
        # }
        # requests.request(method='POST',
        #                  url='http://127.0.0.1:8000/test/',
        #                  files=file_dict)
    
        pass
    
    
    def param_auth():
        from requests.auth import HTTPBasicAuth, HTTPDigestAuth
    
        ret = requests.get('https://api.github.com/user', auth=HTTPBasicAuth('wupeiqi', 'sdfasdfasdf'))
        print(ret.text)
    
        # ret = requests.get('http://192.168.1.1',
        # auth=HTTPBasicAuth('admin', 'admin'))
        # ret.encoding = 'gbk'
        # print(ret.text)
    
        # ret = requests.get('http://httpbin.org/digest-auth/auth/user/pass', auth=HTTPDigestAuth('user', 'pass'))
        # print(ret)
        #
    
    
    def param_timeout():
        # ret = requests.get('http://google.com/', timeout=1)
        # print(ret)
    
        # ret = requests.get('http://google.com/', timeout=(5, 1))
        # print(ret)
        pass
    
    
    def param_allow_redirects():
        ret = requests.get('http://127.0.0.1:8000/test/', allow_redirects=False)
        print(ret.text)
    
    
    def param_proxies():
        # proxies = {
        # "http": "61.172.249.96:80",
        # "https": "http://61.185.219.126:3128",
        # }
    
        # proxies = {'http://10.20.1.128': 'http://10.10.1.10:5323'}
    
        # ret = requests.get("http://www.proxy360.cn/Proxy", proxies=proxies)
        # print(ret.headers)
    
    
        # from requests.auth import HTTPProxyAuth
        #
        # proxyDict = {
        # 'http': '77.75.105.165',
        # 'https': '77.75.105.165'
        # }
        # auth = HTTPProxyAuth('username', 'mypassword')
        #
        # r = requests.get("http://www.google.com", proxies=proxyDict, auth=auth)
        # print(r.text)
    
        pass
    
    
    def param_stream():
        ret = requests.get('http://127.0.0.1:8000/test/', stream=True)
        print(ret.content)
        ret.close()
    
        # from contextlib import closing
        # with closing(requests.get('http://httpbin.org/get', stream=True)) as r:
        # # 在此处理响应。
        # for i in r.iter_content():
        # print(i)
    
    
    def requests_session():
        import requests
    
        session = requests.Session()
    
        ### 1、首先登陆任何页面,获取cookie
    
        i1 = session.get(url="http://dig.chouti.com/help/service")
    
        ### 2、用户登陆,携带上一次的cookie,后台对cookie中的 gpsd 进行授权
        i2 = session.post(
            url="http://dig.chouti.com/login",
            data={
                'phone': "8615131255089",
                'password': "xxxxxx",
                'oneMonth': ""
            }
        )
    
        i3 = session.post(
            url="http://dig.chouti.com/link/vote?linksId=8589623",
        )
        print(i3.text)
    参数示例

    官方文档:http://cn.python-requests.org/zh_CN/latest/user/quickstart.html#id4

    BeautifulSoup

    BeautifulSoup是一个模块,该模块用于接收一个HTML或XML字符串,然后将其进行格式化,之后遍可以使用他提供的方法进行快速查找指定元素,从而使得在HTML或XML中查找指定元素变得简单。

    静态网页:“.html”、“.htm”、“.shtml”、“.shtm”
    其它程序网页:“.php”、“.asp”、“.aspx”、“.jsp”

    from bs4 import BeautifulSoup
     
    
    html_doc = """
    <html><head><title>The Dormouse's story</title></head>
    <body>
    asdf
        <div class="title">
            <b>The Dormouse's story总共</b>
            <h1>f</h1>
        </div>
    <div class="story">Once upon a time there were three little sisters; and their names were
        <a  class="sister0" id="link1">Els<span>f</span>ie</a>,
        <a href="http://example.com/lacie" class="sister" id="link2">Lacie</a> and
        <a href="http://example.com/tillie" class="sister" id="link3">Tillie</a>;
    and they lived at the bottom of a well.</div>
    ad<br/>sf
    <p class="story">...</p>
    </body>
    </html>
    
    """
    
    soup = BeautifulSoup(html, "html.parser")
    # soup
    = BeautifulSoup(html_doc, features="lxml") # 找到第一个a标签 tag1 = soup.find(name='a') # 找到所有的a标签 tag2 = soup.find_all(name='a') # 找到id=link2的标签 tag3 = soup.select('#link2')

    安装:

    pip3 install beautifulsoup4 

    使用示例:

    from bs4 import BeautifulSoup
    html_doc = """
    <html><head><title>The Dormouse's story</title></head>
    <body>
        ...
    </body>
    </html>
    """
    
    soup = BeautifulSoup(html_doc, features="lxml")

     1. name,标签名称

    # tag = soup.find('a')
    
    # name = tag.name # 获取
    
    # print(name)
    
    # tag.name = 'span' # 设置
    
    # print(soup)
    View Code

    2. attr,标签属性

    # tag = soup.find('a')
    
    # attrs = tag.attrs    # 获取
    
    # print(attrs)
    
    # tag.attrs = {'ik':123} # 设置
    
    # tag.attrs['id'] = 'iiiii' # 设置
    
    # print(soup)
    View Code

    3. children,所有子标签

    # body = soup.find('body')
    
    # v = body.children
    View Code

    4. children,所有子子孙孙标签

    # body = soup.find('body')
    
    # v = body.descendants 
    View Code

    5. clear,将标签的所有子标签全部清空(保留标签名)

    # tag = soup.find('body')
    
    # tag.clear()
    
    # print(soup)
    View Code

    6. decompose,递归的删除所有的标签

    # body = soup.find('body')
    
    # body.decompose()
    
    # print(soup) 
    View Code

    7. extract,递归的删除所有的标签,并获取删除的标签

    # body = soup.find('body')
    
    # v = body.extract()
    
    # print(soup)
    View Code

    8. decode,转换为字符串(含当前标签);decode_contents(不含当前标签)

    # body = soup.find('body')
    
    # v = body.decode()
    
    # v = body.decode_contents()
    
    # print(v)
    View Code

    9. encode,转换为字节(含当前标签);encode_contents(不含当前标签)

    # body = soup.find('body')
    
    # v = body.encode()
    
    # v = body.encode_contents()
    
    # print(v) 
    View Code

    10. find,获取匹配的第一个标签

    # tag = soup.find('a')
    
    # print(tag)
    
    # tag = soup.find(name='a', attrs={'class': 'sister'}, recursive=True, text='Lacie')
    
    # tag = soup.find(name='a', class_='sister', recursive=True, text='Lacie')
    
    # print(tag) 
    View Code

    11. find_all,获取匹配的所有标签

    # tags = soup.find_all('a')
    
    # print(tags)
    
     
    
    # tags = soup.find_all('a',limit=1)
    
    # print(tags)
    
     
    
    # tags = soup.find_all(name='a', attrs={'class': 'sister'}, recursive=True, text='Lacie')
    
    # # tags = soup.find(name='a', class_='sister', recursive=True, text='Lacie')
    
    # print(tags)
    
     
    
     
    
    # ####### 列表 #######
    
    # v = soup.find_all(name=['a','div'])
    
    # print(v)
    
     
    
    # v = soup.find_all(class_=['sister0', 'sister'])
    
    # print(v)
    
     
    
    # v = soup.find_all(text=['Tillie'])
    
    # print(v, type(v[0]))
    
     
    
     
    
    # v = soup.find_all(id=['link1','link2'])
    
    # print(v)
    
     
    
    # v = soup.find_all(href=['link1','link2'])
    
    # print(v)
    
     
    
    # ####### 正则 #######
    
    import re
    
    # rep = re.compile('p')
    
    # rep = re.compile('^p')
    
    # v = soup.find_all(name=rep)
    
    # print(v)
    
     
    
    # rep = re.compile('sister.*')
    
    # v = soup.find_all(class_=rep)
    
    # print(v)
    
     
    
    # rep = re.compile('http://www.oldboy.com/static/.*')
    
    # v = soup.find_all(href=rep)
    
    # print(v)
    
     
    
    # ####### 方法筛选 #######
    
    # def func(tag):
    
    # return tag.has_attr('class') and tag.has_attr('id')
    
    # v = soup.find_all(name=func)
    
    # print(v)
    
     
    
     
    
    # ## get,获取标签属性
    
    # tag = soup.find('a')
    
    # v = tag.get('id')
    
    # print(v)
    View Code

    12. has_attr,检查标签是否具有该属性

    # tag = soup.find('a')
    
    # v = tag.has_attr('id')
    
    # print(v) 
    View Code

    13. get_text,获取标签内部文本内容

    # tag = soup.find('a')
    
    # v = tag.get_text('id')
    
    # print(v)
    View Code

    14. index,检查标签在某标签中的索引位置

    # tag = soup.find('body')
    
    # v = tag.index(tag.find('div'))
    
    # print(v)
    
     
    
    # tag = soup.find('body')
    
    # for i,v in enumerate(tag):
    
    # print(i,v)
    View Code

    15. is_empty_element,是否是空标签(是否可以是空)或者自闭合标签,

         判断是否是如下标签:'br' , 'hr', 'input', 'img', 'meta','spacer', 'link', 'frame', 'base'

    # tag = soup.find('br')
    
    # v = tag.is_empty_element
    
    # print(v)
    View Code

    16. 当前的关联标签

    # soup.next
    
    # soup.next_element
    
    # soup.next_elements
    
    # soup.next_sibling
    
    # soup.next_siblings
    
     
    
    #
    
    # tag.previous
    
    # tag.previous_element
    
    # tag.previous_elements
    
    # tag.previous_sibling
    
    # tag.previous_siblings
    
     
    
    #
    
    # tag.parent
    
    # tag.parents
    View Code

    17. 查找某标签的关联标签

    # tag.find_next(...)
    
    # tag.find_all_next(...)
    
    # tag.find_next_sibling(...)
    
    # tag.find_next_siblings(...)
    
     
    
    # tag.find_previous(...)
    
    # tag.find_all_previous(...)
    
    # tag.find_previous_sibling(...)
    
    # tag.find_previous_siblings(...)
    
     
    
    # tag.find_parent(...)
    
    # tag.find_parents(...)
    
     
    
    # 参数同find_
    View Code

    18. select,select_one, CSS选择器

    soup.select("title")
    
     
    
    soup.select("p nth-of-type(3)")
    
     
    
    soup.select("body a")
    
     
    
    soup.select("html head title")
    
     
    
    tag = soup.select("span,a")
    
     
    
    soup.select("head > title")
    
     
    
    soup.select("p > a")
    
     
    
    soup.select("p > a:nth-of-type(2)")
    
     
    
    soup.select("p > #link1")
    
     
    
    soup.select("body > a")
    
     
    
    soup.select("#link1 ~ .sister")
    
     
    
    soup.select("#link1 + .sister")
    
     
    
    soup.select(".sister")
    
     
    
    soup.select("[class~=sister]")
    
     
    
    soup.select("#link1")
    
     
    
    soup.select("a#link2")
    
     
    
    soup.select('a[href]')
    
     
    
    soup.select('a[href="http://example.com/elsie"]')
    
     
    
    soup.select('a[href^="http://example.com/"]')
    
     
    
    soup.select('a[href$="tillie"]')
    
     
    
    soup.select('a[href*=".com/el"]')
    
     
    
     
    
    from bs4.element import Tag
    
     
    
    def default_candidate_generator(tag):
    
        for child in tag.descendants:
    
            if not isinstance(child, Tag):
    
                continue
    
            if not child.has_attr('href'):
    
                continue
    
            yield child
    
     
    
    tags = soup.find('body').select("a", _candidate_generator=default_candidate_generator)
    
    print(type(tags), tags)
    
     
    
    from bs4.element import Tag
    
    def default_candidate_generator(tag):
    
        for child in tag.descendants:
    
            if not isinstance(child, Tag):
    
                continue
    
            if not child.has_attr('href'):
    
                continue
    
            yield child
    
     
    
    tags = soup.find('body').select("a", _candidate_generator=default_candidate_generator, limit=1)
    
    print(type(tags), tags)
    View Code

    19. 标签的内容

    # tag = soup.find('span')
    
    # print(tag.string)          # 获取
    
    # tag.string = 'new content' # 设置
    
    # print(soup)
    
     
    
    # tag = soup.find('body')
    
    # print(tag.string)
    
    # tag.string = 'xxx'
    
    # print(soup)
    
     
    
    # tag = soup.find('body')
    
    # v = tag.stripped_strings  # 递归内部获取所有标签的文本
    
    # print(v)
    View Code

    20.append在当前标签内部追加一个标签

    # tag = soup.find('body')
    
    # tag.append(soup.find('a'))
    
    # print(soup)
    
    #
    
    # from bs4.element import Tag
    
    # obj = Tag(name='i',attrs={'id': 'it'})
    
    # obj.string = '我是一个新来的'
    
    # tag = soup.find('body')
    
    # tag.append(obj)
    
    # print(soup)
    View Code

    21.insert在当前标签内部指定位置插入一个标签

    # from bs4.element import Tag
    
    # obj = Tag(name='i', attrs={'id': 'it'})
    
    # obj.string = '我是一个新来的'
    
    # tag = soup.find('body')
    
    # tag.insert(2, obj)
    
    # print(soup)
    View Code

    22. insert_after,insert_before 在当前标签后面或前面插入

    # from bs4.element import Tag
    
    # obj = Tag(name='i', attrs={'id': 'it'})
    
    # obj.string = '我是一个新来的'
    
    # tag = soup.find('body')
    
    # # tag.insert_before(obj)
    
    # tag.insert_after(obj)
    
    # print(soup)
    View Code

    23. replace_with 在当前标签替换为指定标签

    # from bs4.element import Tag
    
    # obj = Tag(name='i', attrs={'id': 'it'})
    
    # obj.string = '我是一个新来的'
    
    # tag = soup.find('div')
    
    # tag.replace_with(obj)
    
    # print(soup) 
    View Code

    24. 创建标签之间的关系

    # tag = soup.find('div')
    
    # a = soup.find('a')
    
    # tag.setup(previous_sibling=a)
    
    # print(tag.previous_sibling)
    View Code

    25. wrap,将指定标签把当前标签包裹起来

    # from bs4.element import Tag
    
    # obj1 = Tag(name='div', attrs={'id': 'it'})
    
    # obj1.string = '我是一个新来的'
    
    #
    
    # tag = soup.find('a')
    
    # v = tag.wrap(obj1)
    
    # print(soup)
    
     
    
    # tag = soup.find('a')
    
    # v = tag.wrap(soup.find('p'))
    
    # print(soup)
    View Code

    26. unwrap,去掉当前标签,将保留其包裹的标签

    # tag = soup.find('a')
    
    # v = tag.unwrap()
    
    # print(soup) 
    View Code

    更多参数官方:http://beautifulsoup.readthedocs.io/zh_CN/v4.4.0/

    简单爬虫练习

    import requests
    from bs4 import BeautifulSoup
    
    requests = requests.get('http://www.autohome.com.cn/news/')
    
    # 将字节数据转换成字符串
    # requests.content  这个取到的是字节数据
    requests.encoding = 'gbk'
    # requests.text  # 取文本
    # html.parser  html解析器
    
    soup = BeautifulSoup(requests.text, 'html.parser')
    
    tag = soup.find(id='auto-channel-lazyload-article')
    
    h3 = tag.find(name='h3')
    
    print(h3)
    汽车之家试手
    import requests
    from bs4 import BeautifulSoup
    
    response = requests.get('http://www.autohome.com.cn/news/')
    response.encoding = 'gbk'
    soup = BeautifulSoup(response.text, 'html.parser')
    
    li_list = soup.find(id='auto-channel-lazyload-article').find_all(name='li')
    
    for li in li_list:
        titile = li.find('h3').text
        if not titile:
            continue
    
        summary = li.find('p').text
    
        # li.find('a').attrs  获取的是一个字典
        # li.find('a').attrs['href']
        url = li.find('a').get('href')
        img = li.find('img').get('src')
        print(titile, url, summary, img)
    
        res = requests.get(img)
    
        file_name = "%s.jpg" % (titile)
    
        with open(file_name, 'wb') as f:
            f.write(res.content)
    汽车之家

    一大波"自动登陆"示例

    #!/usr/bin/env python
    # -*- coding:utf-8 -*-
    import requests
    
    
    # ############## 方式一 ##############
    """
    # ## 1、首先登陆任何页面,获取cookie
    i1 = requests.get(url="http://dig.chouti.com/help/service")
    i1_cookies = i1.cookies.get_dict()
    
    # ## 2、用户登陆,携带上一次的cookie,后台对cookie中的 gpsd 进行授权
    i2 = requests.post(
        url="http://dig.chouti.com/login",
        data={
            'phone': "8615131255089",
            'password': "xxooxxoo",
            'oneMonth': ""
        },
        cookies=i1_cookies
    )
    
    # ## 3、点赞(只需要携带已经被授权的gpsd即可)
    gpsd = i1_cookies['gpsd']
    i3 = requests.post(
        url="http://dig.chouti.com/link/vote?linksId=8589523",
        cookies={'gpsd': gpsd}
    )
    
    print(i3.text)
    """
    
    
    # ############## 方式二开始不推荐 ##############
    """
    import requests
    
    session = requests.Session()
    i1 = session.get(url="http://dig.chouti.com/help/service")
    i2 = session.post(
        url="http://dig.chouti.com/login",
        data={
            'phone': "8615131255089",
            'password': "xxooxxoo",
            'oneMonth': ""
        }
    )
    i3 = session.post(
        url="http://dig.chouti.com/link/vote?linksId=8589523"
    )
    print(i3.text)
    
    """
    抽屉新热榜
    import requests
    from bs4 import BeautifulSoup
    
    # 获取token
    r1 = requests.get('https://github.com/login')
    s1 = BeautifulSoup(r1.text, 'html.parser')
    token = s1.find(name='input', attrs={'name': "authenticity_token"}).get('value')
    r1_cookie_dict = r1.cookies.get_dict()
    
    r2 = requests.post(
        'https://github.com/session',
        data={
            'utf8': "",
            'authenticity_token': token,
            'login': '317828332@qq.com',
            'password': 'alex3714',
            'commit': 'Sign in'
        },
        cookies=r1_cookie_dict
    )
    
    r2_cookie_dict = r2.cookies.get_dict()
    cookie_dict = {}
    cookie_dict.update(r1_cookie_dict)
    cookie_dict.update(r2_cookie_dict)
    
    r3 = requests.get(
        url='https://github.com/settings/emails',
        cookies=cookie_dict
    )
    print(r3.text)
    github

     参考:http://www.cnblogs.com/wupeiqi/articles/6283017.html

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  • 原文地址:https://www.cnblogs.com/domestique/p/7445961.html
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