• 爬虫


      一、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。

    1、GET请求

     1 # 1、无参数实例
     2   
     3 import requests
     4   
     5 ret = requests.get('https://github.com/timeline.json')
     6   
     7 print ret.url
     8 print ret.text
     9   
    10   
    11   
    12 # 2、有参数实例
    13   
    14 import requests
    15   
    16 payload = {'key1': 'value1', 'key2': 'value2'}
    17 ret = requests.get("http://httpbin.org/get", params=payload)
    18   
    19 print ret.url
    20 print ret.text

    2、POST请求

     1 # 1、基本POST实例
     2   
     3 import requests
     4   
     5 payload = {'key1': 'value1', 'key2': 'value2'}
     6 ret = requests.post("http://httpbin.org/post", data=payload)
     7   
     8 print ret.text
     9   
    10   
    11 # 2、发送请求头和数据实例
    12   
    13 import requests
    14 import json
    15   
    16 url = 'https://api.github.com/some/endpoint'
    17 payload = {'some': 'data'}
    18 headers = {'content-type': 'application/json'}
    19   
    20 ret = requests.post(url, data=json.dumps(payload), headers=headers)
    21   
    22 print ret.text
    23 print ret.cookies

    3、其他

    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)

    4、更多参数

     1 def request(method, url, **kwargs):
     2     """Constructs and sends a :class:`Request <Request>`.
     3 
     4     :param method: method for the new :class:`Request` object.
     5     :param url: URL for the new :class:`Request` object.
     6     :param params: (optional) Dictionary or bytes to be sent in the query string for the :class:`Request`.
     7     :param data: (optional) Dictionary, bytes, or file-like object to send in the body of the :class:`Request`.
     8     :param json: (optional) json data to send in the body of the :class:`Request`.
     9     :param headers: (optional) Dictionary of HTTP Headers to send with the :class:`Request`.
    10     :param cookies: (optional) Dict or CookieJar object to send with the :class:`Request`.
    11     :param files: (optional) Dictionary of ``'name': file-like-objects`` (or ``{'name': file-tuple}``) for multipart encoding upload.
    12         ``file-tuple`` can be a 2-tuple ``('filename', fileobj)``, 3-tuple ``('filename', fileobj, 'content_type')``
    13         or a 4-tuple ``('filename', fileobj, 'content_type', custom_headers)``, where ``'content-type'`` is a string
    14         defining the content type of the given file and ``custom_headers`` a dict-like object containing additional headers
    15         to add for the file.
    16     :param auth: (optional) Auth tuple to enable Basic/Digest/Custom HTTP Auth.
    17     :param timeout: (optional) How long to wait for the server to send data
    18         before giving up, as a float, or a :ref:`(connect timeout, read
    19         timeout) <timeouts>` tuple.
    20     :type timeout: float or tuple
    21     :param allow_redirects: (optional) Boolean. Set to True if POST/PUT/DELETE redirect following is allowed.
    22     :type allow_redirects: bool
    23     :param proxies: (optional) Dictionary mapping protocol to the URL of the proxy.
    24     :param verify: (optional) whether the SSL cert will be verified. A CA_BUNDLE path can also be provided. Defaults to ``True``.
    25     :param stream: (optional) if ``False``, the response content will be immediately downloaded.
    26     :param cert: (optional) if String, path to ssl client cert file (.pem). If Tuple, ('cert', 'key') pair.
    27     :return: :class:`Response <Response>` object
    28     :rtype: requests.Response
    29 
    30     Usage::
    31 
    32       >>> import requests
    33       >>> req = requests.request('GET', 'http://httpbin.org/get')
    34       <Response [200]>
    35     """
    request参数

    5、参数事例

      1 def param_method_url():
      2     # requests.request(method='get', url='http://127.0.0.1:8000/test/')
      3     # requests.request(method='post', url='http://127.0.0.1:8000/test/')
      4     pass
      5 
      6 
      7 def param_param():
      8     # - 可以是字典
      9     # - 可以是字符串
     10     # - 可以是字节(ascii编码以内)
     11 
     12     # requests.request(method='get',
     13     # url='http://127.0.0.1:8000/test/',
     14     # params={'k1': 'v1', 'k2': '水电费'})
     15 
     16     # requests.request(method='get',
     17     # url='http://127.0.0.1:8000/test/',
     18     # params="k1=v1&k2=水电费&k3=v3&k3=vv3")
     19 
     20     # requests.request(method='get',
     21     # url='http://127.0.0.1:8000/test/',
     22     # params=bytes("k1=v1&k2=k2&k3=v3&k3=vv3", encoding='utf8'))
     23 
     24     # 错误
     25     # requests.request(method='get',
     26     # url='http://127.0.0.1:8000/test/',
     27     # params=bytes("k1=v1&k2=水电费&k3=v3&k3=vv3", encoding='utf8'))
     28     pass
     29 
     30 
     31 def param_data():
     32     # 可以是字典
     33     # 可以是字符串
     34     # 可以是字节
     35     # 可以是文件对象
     36 
     37     # requests.request(method='POST',
     38     # url='http://127.0.0.1:8000/test/',
     39     # data={'k1': 'v1', 'k2': '水电费'})
     40 
     41     # requests.request(method='POST',
     42     # url='http://127.0.0.1:8000/test/',
     43     # data="k1=v1; k2=v2; k3=v3; k3=v4"
     44     # )
     45 
     46     # requests.request(method='POST',
     47     # url='http://127.0.0.1:8000/test/',
     48     # data="k1=v1;k2=v2;k3=v3;k3=v4",
     49     # headers={'Content-Type': 'application/x-www-form-urlencoded'}
     50     # )
     51 
     52     # requests.request(method='POST',
     53     # url='http://127.0.0.1:8000/test/',
     54     # data=open('data_file.py', mode='r', encoding='utf-8'), # 文件内容是:k1=v1;k2=v2;k3=v3;k3=v4
     55     # headers={'Content-Type': 'application/x-www-form-urlencoded'}
     56     # )
     57     pass
     58 
     59 
     60 def param_json():
     61     # 将json中对应的数据进行序列化成一个字符串,json.dumps(...)
     62     # 然后发送到服务器端的body中,并且Content-Type是 {'Content-Type': 'application/json'}
     63     requests.request(method='POST',
     64                      url='http://127.0.0.1:8000/test/',
     65                      json={'k1': 'v1', 'k2': '水电费'})
     66 
     67 
     68 def param_headers():
     69     # 发送请求头到服务器端
     70     requests.request(method='POST',
     71                      url='http://127.0.0.1:8000/test/',
     72                      json={'k1': 'v1', 'k2': '水电费'},
     73                      headers={'Content-Type': 'application/x-www-form-urlencoded'}
     74                      )
     75 
     76 
     77 def param_cookies():
     78     # 发送Cookie到服务器端
     79     requests.request(method='POST',
     80                      url='http://127.0.0.1:8000/test/',
     81                      data={'k1': 'v1', 'k2': 'v2'},
     82                      cookies={'cook1': 'value1'},
     83                      )
     84     # 也可以使用CookieJar(字典形式就是在此基础上封装)
     85     from http.cookiejar import CookieJar
     86     from http.cookiejar import Cookie
     87 
     88     obj = CookieJar()
     89     obj.set_cookie(Cookie(version=0, name='c1', value='v1', port=None, domain='', path='/', secure=False, expires=None,
     90                           discard=True, comment=None, comment_url=None, rest={'HttpOnly': None}, rfc2109=False,
     91                           port_specified=False, domain_specified=False, domain_initial_dot=False, path_specified=False)
     92                    )
     93     requests.request(method='POST',
     94                      url='http://127.0.0.1:8000/test/',
     95                      data={'k1': 'v1', 'k2': 'v2'},
     96                      cookies=obj)
     97 
     98 
     99 def param_files():
    100     # 发送文件
    101     # file_dict = {
    102     # 'f1': open('readme', 'rb')
    103     # }
    104     # requests.request(method='POST',
    105     # url='http://127.0.0.1:8000/test/',
    106     # files=file_dict)
    107 
    108     # 发送文件,定制文件名
    109     # file_dict = {
    110     # 'f1': ('test.txt', open('readme', 'rb'))
    111     # }
    112     # requests.request(method='POST',
    113     # url='http://127.0.0.1:8000/test/',
    114     # files=file_dict)
    115 
    116     # 发送文件,定制文件名
    117     # file_dict = {
    118     # 'f1': ('test.txt', "hahsfaksfa9kasdjflaksdjf")
    119     # }
    120     # requests.request(method='POST',
    121     # url='http://127.0.0.1:8000/test/',
    122     # files=file_dict)
    123 
    124     # 发送文件,定制文件名
    125     # file_dict = {
    126     #     'f1': ('test.txt', "hahsfaksfa9kasdjflaksdjf", 'application/text', {'k1': '0'})
    127     # }
    128     # requests.request(method='POST',
    129     #                  url='http://127.0.0.1:8000/test/',
    130     #                  files=file_dict)
    131 
    132     pass
    133 
    134 
    135 def param_auth():
    136     from requests.auth import HTTPBasicAuth, HTTPDigestAuth
    137 
    138     ret = requests.get('https://api.github.com/user', auth=HTTPBasicAuth('wupeiqi', 'sdfasdfasdf'))
    139     print(ret.text)
    140 
    141     # ret = requests.get('http://192.168.1.1',
    142     # auth=HTTPBasicAuth('admin', 'admin'))
    143     # ret.encoding = 'gbk'
    144     # print(ret.text)
    145 
    146     # ret = requests.get('http://httpbin.org/digest-auth/auth/user/pass', auth=HTTPDigestAuth('user', 'pass'))
    147     # print(ret)
    148     #
    149 
    150 
    151 def param_timeout():
    152     # ret = requests.get('http://google.com/', timeout=1)
    153     # print(ret)
    154 
    155     # ret = requests.get('http://google.com/', timeout=(5, 1))
    156     # print(ret)
    157     pass
    158 
    159 
    160 def param_allow_redirects():
    161     ret = requests.get('http://127.0.0.1:8000/test/', allow_redirects=False)
    162     print(ret.text)
    163 
    164 
    165 def param_proxies():
    166     # proxies = {
    167     # "http": "61.172.249.96:80",
    168     # "https": "http://61.185.219.126:3128",
    169     # }
    170 
    171     # proxies = {'http://10.20.1.128': 'http://10.10.1.10:5323'}
    172 
    173     # ret = requests.get("http://www.proxy360.cn/Proxy", proxies=proxies)
    174     # print(ret.headers)
    175 
    176 
    177     # from requests.auth import HTTPProxyAuth
    178     #
    179     # proxyDict = {
    180     # 'http': '77.75.105.165',
    181     # 'https': '77.75.105.165'
    182     # }
    183     # auth = HTTPProxyAuth('username', 'mypassword')
    184     #
    185     # r = requests.get("http://www.google.com", proxies=proxyDict, auth=auth)
    186     # print(r.text)
    187 
    188     pass
    189 
    190 
    191 def param_stream():
    192     ret = requests.get('http://127.0.0.1:8000/test/', stream=True)
    193     print(ret.content)
    194     ret.close()
    195 
    196     # from contextlib import closing
    197     # with closing(requests.get('http://httpbin.org/get', stream=True)) as r:
    198     # # 在此处理响应。
    199     # for i in r.iter_content():
    200     # print(i)
    201 
    202 
    203 def requests_session():
    204     import requests
    205 
    206     session = requests.Session()
    207 
    208     ### 1、首先登陆任何页面,获取cookie
    209 
    210     i1 = session.get(url="http://dig.chouti.com/help/service")
    211 
    212     ### 2、用户登陆,携带上一次的cookie,后台对cookie中的 gpsd 进行授权
    213     i2 = session.post(
    214         url="http://dig.chouti.com/login",
    215         data={
    216             'phone': "8615131255089",
    217             'password': "xxxxxx",
    218             'oneMonth': ""
    219         }
    220     )
    221 
    222     i3 = session.post(
    223         url="http://dig.chouti.com/link/vote?linksId=8589623",
    224     )
    225     print(i3.text)
    226 
    227 参数示例
    View Code

    二、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。

     1 from bs4 import BeautifulSoup
     2  
     3 html_doc = """
     4 <html><head><title>The Dormouse's story</title></head>
     5 <body>
     6 asdf
     7     <div class="title">
     8         <b>The Dormouse's story总共</b>
     9         <h1>f</h1>
    10     </div>
    11 <div class="story">Once upon a time there were three little sisters; and their names were
    12     <a  class="sister0" id="link1">Els<span>f</span>ie</a>,
    13     <a href="http://example.com/lacie" class="sister" id="link2">Lacie</a> and
    14     <a href="http://example.com/tillie" class="sister" id="link3">Tillie</a>;
    15 and they lived at the bottom of a well.</div>
    16 ad<br/>sf
    17 <p class="story">...</p>
    18 </body>
    19 </html>
    20 """
    21  
    22 soup = BeautifulSoup(html_doc, features="lxml")
    23 # 找到第一个a标签
    24 tag1 = soup.find(name='a')
    25 # 找到所有的a标签
    26 tag2 = soup.find_all(name='a')
    27 # 找到id=link2的标签
    28 tag3 = soup.select('#link2')

    安装方法:

    pip3 install beautifulsoup4

    使用实例:

    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:

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

    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)

    3. children,所有子标签

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

    4. children,所有子子孙孙标签

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

    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)

    6. decompose,递归的删除所有的标签

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

    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)

    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)

    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)

    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)

    11、find_all,获取匹配的所有标签

     1 # tags = soup.find_all('a')
     2 # print(tags)
     3  
     4 # tags = soup.find_all('a',limit=1)
     5 # print(tags)
     6  
     7 # tags = soup.find_all(name='a', attrs={'class': 'sister'}, recursive=True, text='Lacie')
     8 # # tags = soup.find(name='a', class_='sister', recursive=True, text='Lacie')
     9 # print(tags)
    10  
    11  
    12 # ####### 列表 #######
    13 # v = soup.find_all(name=['a','div'])
    14 # print(v)
    15  
    16 # v = soup.find_all(class_=['sister0', 'sister'])
    17 # print(v)
    18  
    19 # v = soup.find_all(text=['Tillie'])
    20 # print(v, type(v[0]))
    21  
    22  
    23 # v = soup.find_all(id=['link1','link2'])
    24 # print(v)
    25  
    26 # v = soup.find_all(href=['link1','link2'])
    27 # print(v)
    28  
    29 # ####### 正则 #######
    30 import re
    31 # rep = re.compile('p')
    32 # rep = re.compile('^p')
    33 # v = soup.find_all(name=rep)
    34 # print(v)
    35  
    36 # rep = re.compile('sister.*')
    37 # v = soup.find_all(class_=rep)
    38 # print(v)
    39  
    40 # rep = re.compile('http://www.oldboy.com/static/.*')
    41 # v = soup.find_all(href=rep)
    42 # print(v)
    43  
    44 # ####### 方法筛选 #######
    45 # def func(tag):
    46 # return tag.has_attr('class') and tag.has_attr('id')
    47 # v = soup.find_all(name=func)
    48 # print(v)
    49  
    50  
    51 # ## get,获取标签属性
    52 # tag = soup.find('a')
    53 # v = tag.get('id')
    54 # print(v)

    12. has_attr,检查标签是否具有该属性

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  • 原文地址:https://www.cnblogs.com/bravexz/p/7691661.html
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