爬虫

 requests

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 注意：
   requests.post(url='',json=payload) #默认请求头为‘application/json’
   requests.post(url='',data=payload) #默认请求头为'application/x-www-form-/urlencoded'
20 ret = requests.post(url, data=json.dumps(payload), headers=headers) 

21 ret = requests.post(url, json=payload, headers=headers)
   ret = requests.post(url, data=payload, headers={'content-type': 'application/x-www-form-/urlencoded'})
22 print ret.text 
23 print ret.cookies

 

 

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)

 

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     """
View Code
  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)
参数示例

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。

处理依赖

1
pip3 install beautifulsoup4

使用示例：

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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)

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

# 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)

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)

13. get_text,获取标签内部文本内容

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

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)

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)

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

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_all

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)

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)

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)

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)

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)

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)

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)

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)

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)

后台插件过滤：

View Code

 

基于__new__实现单例模式示例：

View Code
posted @ 2017-08-28 17:52  柳姑娘  阅读(127)  评论(0)    收藏  举报