爬虫-request和BeautifulSoup模块

requests简介

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、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)

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`.

    :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.

        ``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.

    :param timeout: (optional) How long to wait for the server to send data

        before giving up, as a float, or a :ref:`(connect timeout, read

        timeout) <timeouts>` tuple.

    :type timeout: float or tuple

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

    :type allow_redirects: bool

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

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

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

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

    :return: :class:`Response <Response>` object

    :rtype: requests.Response

    Usage::

      >>> import requests

      >>> req = requests.request('GET', 'http://httpbin.org/get')

      <Response [200]>

    """

参数列表

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)

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。

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_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)

2. attr，标签属性

# tag = soup.find('a')

# attrs = tag.attrs # 获取属性

# print(attrs)

# tag.attrs = {'ik': 123}  # 设置

# tag.attrs['id'] = 'v'  # 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）

# body = soup.find('body')

# body.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)

# 使用class进行寻找的时候避免关键字，使用'class_'

11. find_all,获取匹配的所有标签

# tag = soup.find_all('a')

# print(tag)

# tags = soup.find_all('a', limit=1)  # 匹配到的第一个a标签

# 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)  # recursive 递归查找

# ##### 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)

巴特西