django高级之爬虫基础

目录：

• 爬虫原理
• requests模块
• beautifulsoup模块
• 爬虫自动登陆示例

一、爬虫原理

Python非常适合用来开发网页爬虫，理由如下：
1、抓取网页本身的接口
相比与其他静态编程语言，如java，c#，c++，python抓取网页文档的接口更简洁；相比其他动态脚本语言，如perl，shell，python的urllib包提供了较为完整的访问网页文档的API。（当然ruby也是很好的选择）
此外，抓取网页有时候需要模拟浏览器的行为，很多网站对于生硬的爬虫抓取都是封杀的。这是我们需要模拟user agent的行为构造合适的请求，譬如模拟用户登陆、模拟session/cookie的存储和设置。在python里都有非常优秀的第三方包帮你搞定，如Requests，mechanize

2、网页抓取后的处理
抓取的网页通常需要处理，比如过滤html标签，提取文本等。python的beautifulsoap提供了简洁的文档处理功能，能用极短的代码完成大部分文档的处理。
其实以上功能很多语言和工具都能做，但是用python能够干得最快，最干净。

3、爬虫架构

URL管理器：管理待爬取的url集合和已爬取的url集合，传送待爬取的url给网页下载器。
网页下载器（urllib、requests）：爬取url对应的网页，存储成字符串或文件，传送给网页解析器。
网页解析器（BeautifulSoup）：解析出有价值的数据，存储下来，同时补充url到URL管理器。

4、运行流程

5、HTTP请求内容

GET:

http GET /index.html?p=1 http1.1\r\nhost:oldboyedu.com\r\n....\r\n\r\

默认请求头：Content-Type:text/html; charset=utf-8
无请求体

POST:

http POST / http1.1\r\nhost:oldboyedu.com\r\n....\r\n\r\nname=alex&age=18

默认请求头：content-type:application/url-from
请求体：\r\n\r\nname=alex&age=18

http POST / http1.1\r\nhost:oldboyedu.com\r\n....\r\n\r\n{"name": "alex", "age": 18}

默认请求头：content-type:application/json
请求体：\r\n\r\n{"name": "alex", "age": 18}

ps.响应：

- 响应：
   响应头
      - 浏览器读取
   响应体
      - 看到的内容

6、提高爬虫性能

【协程】异步非阻塞，并在网页解析器（BeautifulSoup）使用lxml模块（为c语言写的规则模块，效率高）解析。

7、待补充：

二、requests模块

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

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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) # 等价于request.post(url,json=payload)
21   
22 print ret.text
23 print ret.cookies

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3、其他请求

 1 requests.get(url, params=None, **kwargs)
 2 requests.post(url, data=None, json=None, **kwargs)
 3 requests.put(url, data=None, **kwargs)
 4 requests.head(url, **kwargs)
 5 requests.delete(url, **kwargs)
 6 requests.patch(url, data=None, **kwargs)
 7 requests.options(url, **kwargs)
 8   
 9 # 以上方法均是在此方法的基础上构建
10 requests.request(method, url, **kwargs)

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4、更多参数

method：请求类型（GET、POST、delete、put、head、patch、options）

url：访问地址
Params：在 QueryString、Form、Server Variable 以及 Cookies 找数据，他首先在 QueryString 集合查找数据，如果在 QueryString 找到数据，就返回数据，如果没有找到就去 Form 集合中查找数据，找到就返回，否则在往下一下个集合查找数据。是所有post和get传过来的值的集合

data（json）： POST类型所带参数，声名发送请求体的格式

headers：定制头部信息

cookies：定制cookies信息

files：文件处理

(optional) Dictionary of ``'name': file-like-objects`` (or ``{'name': file-tuple}``) for multipart encoding upload.
        ``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.

auth：登陆使用，适用于类似ftp之类封装好的简单登陆验证。

(optional) Auth tuple to enable Basic/Digest/Custom HTTP Auth.

timeout：请求等待响应多长时间，数据发送多长时间。 仅对连接过程有效，与响应体的下载无关。

 (optional) How long to wait for the server to send data
        before giving up, as a float, or a :ref:`(connect timeout, read
        timeout) ` tuple.

allow_redirects：网络请求中可能会遇到重定向，我们需要一次处理一个请求，可以把重定向禁止。模拟打开

(optional) Boolean. Set to True if POST/PUT/DELETE redirect following is allowed.

proxies：代理访问配置。

(optional) Dictionary mapping protocol to the URL of the proxy.

verify：https是否访问开启，配合cert的CA证书使用

 (optional) whether the SSL cert will be verified. A CA_BUNDLE path can also be provided. Defaults to ``True``.

stream：(optional) if ``False``, the response content will be immediately downloaded.

1 块编码请求
2 对于出去和进来的请求，Requests 也支持分块传输编码。要发送一个块编码的请求，仅需为你的请求体提供一个生成器（或任意没有具体长度的迭代器）：
3 
4 def gen():
5     yield 'hi'
6     yield 'there'
7 
8 requests.post('http://some.url/chunked', data=gen())
9 对于分块的编码请求，我们最好使用 Response.iter_content() 对其数据进行迭代。在理想情况下，你的 request 会设置 stream=True，这样你就可以通过调用 iter_content 并将分块大小参数设为 None，从而进行分块的迭代。如果你要设置分块的最大体积，你可以把分块大小参数设为任意整数。

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cert：私有证书配置。

(optional) if String, path to ssl client cert file (.pem). If Tuple, ('cert', 'key') pair.

使用方法：

  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)

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

三、beautifulsoup模块

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。

解析器	使用方法	优势	劣势
Python标准库	BeautifulSoup(markup, “html.parser”)	Python的内置标准库 执行速度适中 文档容错能力强	Python 2.7.3 or 3.2.2)前 的版本中文档容错能力差
lxml HTML 解析器	BeautifulSoup(markup, “lxml”)	速度快 文档容错能力强	需要安装C语言库
lxml XML 解析器	BeautifulSoup(markup, [“lxml”, “xml”])BeautifulSoup(markup, “xml”)	速度快 唯一支持XML的解析器	需要安装C语言库
html5lib	BeautifulSoup(markup, “html5lib”)	最好的容错性 以浏览器的方式解析文档 生成HTML5格式的文档	速度慢 不依赖外部扩展

 1 from bs4 import BeautifulSoup
 2  
 3 html_doc = """
 4 
 5 
 6 asdf
 7     

 8         The Dormouse's story总共
 9         
f
10     
11 
Once upon a time there were three little sisters; and their names were
12     Elsfie,
13     Lacie and
14     Tillie;
15 and they lived at the bottom of a well.
16 ad
sf
17 
...
18 
19 
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')

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1、安装

pip3 install beautifulsoup4

2、使用示例：

 1 from bs4 import BeautifulSoup
 2  
 3 html_doc = """
 4 
 5 
 6     ...
 7 
 8 
 9 """
10  
11 soup = BeautifulSoup(html_doc, features="lxml")

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3、name，标签名称（获取，更改）

1 # tag = soup.find('a')
2 # name = tag.name # 获取
3 # print(name)
4 # tag.name = 'span' # 设置
5 # print(soup)

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4、attr，标签属性（获取，更改）

1 # tag = soup.find('a')
2 # attrs = tag.attrs    # 获取
3 # print(attrs)
4 # tag.attrs = {'ik':123} # 设置
5 # tag.attrs['id'] = 'iiiii' # 设置
6 # print(soup)

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5、children,所有子标签（获取）

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

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6、children,所有子子孙孙标签（获取）

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

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7、clear,将标签的所有子标签全部清空（保留标签名）

1 # tag = soup.find('body')
2 # tag.clear()
3 # print(soup)

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8、decompose,递归的删除所有的标签

1 # body = soup.find('body')
2 # body.decompose()
3 # print(soup)

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9、extract,递归的删除所有的标签，并获取删除的标签

1 # body = soup.find('body')
2 # v = body.extract()
3 # print(soup)

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

1 # body = soup.find('body')
2 # v = body.decode()
3 # v = body.decode_contents()
4 # print(v)

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11、 encode,转换为字节（含当前标签）；encode_contents（不含当前标签）

1 # body = soup.find('body')
2 # v = body.encode()
3 # v = body.encode_contents()
4 # print(v)

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12、 find,获取匹配的第一个标签

1 # tag = soup.find('a')
2 # print(tag)
3 # tag = soup.find(name='a', attrs={'class': 'sister'}, recursive=True, text='Lacie')
4 # tag = soup.find(name='a', class_='sister', recursive=True, text='Lacie')
5 # print(tag)

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13、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)

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14、has_attr,检查标签是否具有该属性

1 # tag = soup.find('a')
2 # v = tag.has_attr('id')
3 # print(v)

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15、 get_text,获取标签内部文本内容

1 # tag = soup.find('a')
2 # v = tag.get_text('id')
3 # print(v)

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16、index,检查标签在某标签中的索引位置

1 # tag = soup.find('body')
2 # v = tag.index(tag.find('div'))
3 # print(v)
4  
5 # tag = soup.find('body')
6 # for i,v in enumerate(tag):
7 # print(i,v)

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17、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'

1 # tag = soup.find('br')
2 # v = tag.is_empty_element
3 # print(v)

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18、当前的关联标签

 1 # soup.next 下一个子元素
 2 # soup.next_element list形式下一个子元素
 3 # soup.next_elements list形式所有子元素
 4 # soup.next_sibling 下一个元素的兄弟
 5 # soup.next_siblings  list形式元素的所有兄弟元素
 6  
 7 #
 8 # tag.previous 上一个元素
 9 # tag.previous_element list形式上一个元素
10 # tag.previous_elements list形式上面所有元素
11 # tag.previous_sibling list形式上一个元素的所有兄弟
12 # tag.previous_siblings list形式上所有元素的所有兄弟
13  
14 #
15 # tag.parent 父节点
16 # tag.parents 所有父节点

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19、查找某标签的关联标签

 1 # tag.find_next(...)
 2 # tag.find_all_next(...)
 3 # tag.find_next_sibling(...)
 4 # tag.find_next_siblings(...)
 5  
 6 # tag.find_previous(...)
 7 # tag.find_all_previous(...)
 8 # tag.find_previous_sibling(...)
 9 # tag.find_previous_siblings(...)
10  
11 # tag.find_parent(...)
12 # tag.find_parents(...)
13  
14 # 参数同find_all

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20、 select,select_one, CSS选择器

 1 soup.select("title")
 2  
 3 soup.select("p nth-of-type(3)")
 4  
 5 soup.select("body a")
 6  
 7 soup.select("html head title")
 8  
 9 tag = soup.select("span,a")
10  
11 soup.select("head > title")
12  
13 soup.select("p > a")
14  
15 soup.select("p > a:nth-of-type(2)")
16  
17 soup.select("p > #link1")
18  
19 soup.select("body > a")
20  
21 soup.select("#link1 ~ .sister")
22  
23 soup.select("#link1 + .sister")
24  
25 soup.select(".sister")
26  
27 soup.select("[class~=sister]")
28  
29 soup.select("#link1")
30  
31 soup.select("a#link2")
32  
33 soup.select('a[href]')
34  
35 soup.select('a[href="http://example.com/elsie"]')
36  
37 soup.select('a[href^="http://example.com/"]')
38  
39 soup.select('a[href$="tillie"]')
40  
41 soup.select('a[href*=".com/el"]')
42  
43  
44 from bs4.element import Tag
45  
46 def default_candidate_generator(tag):
47     for child in tag.descendants:
48         if not isinstance(child, Tag):
49             continue
50         if not child.has_attr('href'):
51             continue
52         yield child
53  
54 tags = soup.find('body').select("a", _candidate_generator=default_candidate_generator)
55 print(type(tags), tags)
56  
57 from bs4.element import Tag
58 def default_candidate_generator(tag):
59     for child in tag.descendants:
60         if not isinstance(child, Tag):
61             continue
62         if not child.has_attr('href'):
63             continue
64         yield child
65  
66 tags = soup.find('body').select("a", _candidate_generator=default_candidate_generator, limit=1)
67 print(type(tags), tags)

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21、标签的内容.text（只能取） .string(能取、能改)

 1 # tag = soup.find('span')
 2 # print(tag.string)          # 获取
 3 # tag.string = 'new content' # 设置
 4 # print(soup)
 5  
 6 # tag = soup.find('body')
 7 # print(tag.string)
 8 # tag.string = 'xxx'
 9 # print(soup)
10  
11 # tag = soup.find('body')
12 # v = tag.stripped_strings  # 递归内部获取所有标签的文本

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22.append在当前标签内部追加一个标签

 1 # tag = soup.find('body')
 2 # tag.append(soup.find('a'))
 3 # print(soup)
 4 #
 5 # from bs4.element import Tag
 6 # obj = Tag(name='i',attrs={'id': 'it'})
 7 # obj.string = '我是一个新来的'
 8 # tag = soup.find('body')
 9 # tag.append(obj)
10 # print(soup)

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23、insert在当前标签内部指定位置插入一个标签

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

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24、 insert_after,insert_before 在当前标签后面或前面插入

1 # from bs4.element import Tag
2 # obj = Tag(name='i', attrs={'id': 'it'})
3 # obj.string = '我是一个新来的'
4 # tag = soup.find('body')
5 # # tag.insert_before(obj)
6 # tag.insert_after(obj)
7 # print(soup)

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25、replace_with 在当前标签替换为指定标签

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

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26、创建标签之间的关系

1 # tag = soup.find('div')
2 # a = soup.find('a')
3 # tag.setup(previous_sibling=a)
4 # print(tag.previous_sibling)

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27、wrap，将指定标签把当前标签包裹起来

 1 # from bs4.element import Tag
 2 # obj1 = Tag(name='div', attrs={'id': 'it'})
 3 # obj1.string = '我是一个新来的'
 4 #
 5 # tag = soup.find('a')
 6 # v = tag.wrap(obj1)
 7 # print(soup)
 8  
 9 # tag = soup.find('a')
10 # v = tag.wrap(soup.find('p'))
11 # print(soup)

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28、unwrap，去掉当前标签，将保留其包裹的标签

1 # tag = soup.find('a')
2 # v = tag.unwrap()
3 # print(soup)

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四、自动登陆爬虫示例

1、抽屉

 1 #!/usr/bin/env python
 2 # -*- coding:utf-8 -*-
 3 import requests
 4 
 5 
 6 # ############## 方式一 ##############
 7 """
 8 # ## 1、首先登陆任何页面，获取cookie
 9 i1 = requests.get(url="http://dig.chouti.com/help/service")
10 i1_cookies = i1.cookies.get_dict()
11 
12 # ## 2、用户登陆，携带上一次的cookie，后台对cookie中的 gpsd 进行授权
13 i2 = requests.post(
14     url="http://dig.chouti.com/login",
15     data={
16         'phone': "8615131255089",
17         'password': "xxooxxoo",
18         'oneMonth': ""
19     },
20     cookies=i1_cookies
21 )
22 
23 # ## 3、点赞（只需要携带已经被授权的gpsd即可）
24 gpsd = i1_cookies['gpsd']
25 i3 = requests.post(
26     url="http://dig.chouti.com/link/vote?linksId=8589523",
27     cookies={'gpsd': gpsd}
28 )
29 
30 print(i3.text)
31 """
32 
33 
34 # ############## 方式二 ##############
35 """
36 import requests
37 
38 session = requests.Session()
39 i1 = session.get(url="http://dig.chouti.com/help/service")
40 i2 = session.post(
41     url="http://dig.chouti.com/login",
42     data={
43         'phone': "8615131255089",
44         'password': "xxooxxoo",
45         'oneMonth': ""
46     }
47 )
48 i3 = session.post(
49     url="http://dig.chouti.com/link/vote?linksId=8589523"
50 )
51 print(i3.text)
52 
53 """
54 
55 抽屉新热榜

View Code

2、github

 1 #!/usr/bin/env python
 2 # -*- coding:utf-8 -*-
 3 
 4 import requests
 5 from bs4 import BeautifulSoup
 6 
 7 # ############## 方式一 ##############
 8 #
 9 # # 1. 访问登陆页面，获取 authenticity_token
10 # i1 = requests.get('https://github.com/login')
11 # soup1 = BeautifulSoup(i1.text, features='lxml')
12 # tag = soup1.find(name='input', attrs={'name': 'authenticity_token'})
13 # authenticity_token = tag.get('value')
14 # c1 = i1.cookies.get_dict()
15 # i1.close()
16 #
17 # # 1. 携带authenticity_token和用户名密码等信息，发送用户验证
18 # form_data = {
19 # "authenticity_token": authenticity_token,
20 #     "utf8": "",
21 #     "commit": "Sign in",
22 #     "login": "[email protected]",
23 #     'password': 'xxoo'
24 # }
25 #
26 # i2 = requests.post('https://github.com/session', data=form_data, cookies=c1)
27 # c2 = i2.cookies.get_dict()
28 # c1.update(c2)
29 # i3 = requests.get('https://github.com/settings/repositories', cookies=c1)
30 #
31 # soup3 = BeautifulSoup(i3.text, features='lxml')
32 # list_group = soup3.find(name='div', class_='listgroup')
33 #
34 # from bs4.element import Tag
35 #
36 # for child in list_group.children:
37 #     if isinstance(child, Tag):
38 #         project_tag = child.find(name='a', class_='mr-1')
39 #         size_tag = child.find(name='small')
40 #         temp = "项目:%s(%s); 项目路径:%s" % (project_tag.get('href'), size_tag.string, project_tag.string, )
41 #         print(temp)
42 
43 
44 
45 # ############## 方式二 ##############
46 # session = requests.Session()
47 # # 1. 访问登陆页面，获取 authenticity_token
48 # i1 = session.get('https://github.com/login')
49 # soup1 = BeautifulSoup(i1.text, features='lxml')
50 # tag = soup1.find(name='input', attrs={'name': 'authenticity_token'})
51 # authenticity_token = tag.get('value')
52 # c1 = i1.cookies.get_dict()
53 # i1.close()
54 #
55 # # 1. 携带authenticity_token和用户名密码等信息，发送用户验证
56 # form_data = {
57 #     "authenticity_token": authenticity_token,
58 #     "utf8": "",
59 #     "commit": "Sign in",
60 #     "login": "[email protected]",
61 #     'password': 'xxoo'
62 # }
63 #
64 # i2 = session.post('https://github.com/session', data=form_data)
65 # c2 = i2.cookies.get_dict()
66 # c1.update(c2)
67 # i3 = session.get('https://github.com/settings/repositories')
68 #
69 # soup3 = BeautifulSoup(i3.text, features='lxml')
70 # list_group = soup3.find(name='div', class_='listgroup')
71 #
72 # from bs4.element import Tag
73 #
74 # for child in list_group.children:
75 #     if isinstance(child, Tag):
76 #         project_tag = child.find(name='a', class_='mr-1')
77 #         size_tag = child.find(name='small')
78 #         temp = "项目:%s(%s); 项目路径:%s" % (project_tag.get('href'), size_tag.string, project_tag.string, )
79 #         print(temp)
80 
81 github

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3、知乎

 1 #!/usr/bin/env python
 2 # -*- coding:utf-8 -*-
 3 import time
 4 
 5 import requests
 6 from bs4 import BeautifulSoup
 7 
 8 session = requests.Session()
 9 
10 i1 = session.get(
11     url='https://www.zhihu.com/#signin',
12     headers={
13         'User-Agent': 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/54.0.2840.98 Safari/537.36',
14     }
15 )
16 
17 soup1 = BeautifulSoup(i1.text, 'lxml')
18 xsrf_tag = soup1.find(name='input', attrs={'name': '_xsrf'})
19 xsrf = xsrf_tag.get('value')
20 
21 current_time = time.time()
22 i2 = session.get(
23     url='https://www.zhihu.com/captcha.gif',
24     params={'r': current_time, 'type': 'login'},
25     headers={
26         'User-Agent': 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/54.0.2840.98 Safari/537.36',
27     })
28 
29 with open('zhihu.gif', 'wb') as f:
30     f.write(i2.content)
31 
32 captcha = input('请打开zhihu.gif文件，查看并输入验证码：')
33 form_data = {
34     "_xsrf": xsrf,
35     'password': 'xxooxxoo',
36     "captcha": 'captcha',
37     'email': '[email protected]'
38 }
39 i3 = session.post(
40     url='https://www.zhihu.com/login/email',
41     data=form_data,
42     headers={
43         'User-Agent': 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/54.0.2840.98 Safari/537.36',
44     }
45 )
46 
47 i4 = session.get(
48     url='https://www.zhihu.com/settings/profile',
49     headers={
50         'User-Agent': 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/54.0.2840.98 Safari/537.36',
51     }
52 )
53 
54 soup4 = BeautifulSoup(i4.text, 'lxml')
55 tag = soup4.find(id='rename-section')
56 nick_name = tag.find('span',class_='name').string
57 print(nick_name)
58 
59 知乎

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4、博客园

 1 #!/usr/bin/env python
 2 # -*- coding:utf-8 -*-
 3 import re
 4 import json
 5 import base64
 6 
 7 import rsa
 8 import requests
 9 
10 
11 def js_encrypt(text):
12     b64der = 'MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCp0wHYbg/NOPO3nzMD3dndwS0MccuMeXCHgVlGOoYyFwLdS24Im2e7YyhB0wrUsyYf0/nhzCzBK8ZC9eCWqd0aHbdgOQT6CuFQBMjbyGYvlVYU2ZP7kG9Ft6YV6oc9ambuO7nPZh+bvXH0zDKfi02prknrScAKC0XhadTHT3Al0QIDAQAB'
13     der = base64.standard_b64decode(b64der)
14 
15     pk = rsa.PublicKey.load_pkcs1_openssl_der(der)
16     v1 = rsa.encrypt(bytes(text, 'utf8'), pk)
17     value = base64.encodebytes(v1).replace(b'\n', b'')
18     value = value.decode('utf8')
19 
20     return value
21 
22 
23 session = requests.Session()
24 
25 i1 = session.get('https://passport.cnblogs.com/user/signin')
26 rep = re.compile("'VerificationToken': '(.*)'")
27 v = re.search(rep, i1.text)
28 verification_token = v.group(1)
29 
30 form_data = {
31     'input1': js_encrypt('wptawy'),
32     'input2': js_encrypt('asdfasdf'),
33     'remember': False
34 }
35 
36 i2 = session.post(url='https://passport.cnblogs.com/user/signin',
37                   data=json.dumps(form_data),
38                   headers={
39                       'Content-Type': 'application/json; charset=UTF-8',
40                       'X-Requested-With': 'XMLHttpRequest',
41                       'VerificationToken': verification_token}
42                   )
43 
44 i3 = session.get(url='https://i.cnblogs.com/EditDiary.aspx')
45 
46 print(i3.text)
47 
48 博客园

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转载于:https://www.cnblogs.com/wangshuyang/p/7677571.html