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。

安装

pip3 install requests 

1、GET请求

# 1、无参数实例

import requests

ret = requests.get('https://github.com/timeline.json')

print(ret.content)  # 获取收到的字节内容,bytes类型
print(ret.apparent_encoding)  # 获取当前网站的编码格式
ret.encoding = ret.apparent_encoding  # 设置编码格式
print(ret.url)
print(ret.text)  # 获取解码后的结果

# 2、有参数实例

import requests

payload = {'key1': 'value1', 'key2': 'value2'}  
ret = requests.get("http://httpbin.org/get", params=payload)  # params为url上?后的参数

print(ret.url)
print(ret.text)

带参数的GET请求->headers

#通常我们在发送请求时都需要带上请求头,请求头是将自身伪装成浏览器的关键,常见的有用的请求头如下
Host
Referer #大型网站通常都会根据该参数判断请求的来源
User-Agent #客户端
Cookie #Cookie信息虽然包含在请求头里,但requests模块有单独的参数来处理他,headers={}内就不要放它了


#添加headers(浏览器会识别请求头,不加可能会被拒绝访问,比如访问https://www.zhihu.com/explore)
import requests
response=requests.get('https://www.zhihu.com/explore')
response.status_code #500


#自己定制headers
headers={
    'User-Agent':'Mozilla/5.0 (Linux; Android 6.0; Nexus 5 Build/MRA58N) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/46.0.2490.76 Mobile Safari/537.36',

}
respone=requests.get('https://www.zhihu.com/explore',
                     headers=headers)
print(respone.status_code) #200

带参数的GET请求->cookies

#登录github,然后从浏览器中获取cookies,以后就可以直接拿着cookie登录了,无需输入用户名密码
#用户名:egonlin 邮箱378533872@qq.com 密码lhf@123

import requests

Cookies={   'user_session':'wGMHFJKgDcmRIVvcA14_Wrt_3xaUyJNsBnPbYzEL6L0bHcfc',
}

response=requests.get('https://github.com/settings/emails',
             cookies=Cookies) #github对请求头没有什么限制,我们无需定制user-agent,对于其他网站可能还需要定制


print('378533872@qq.com' in response.text) #True

 

2、POST请求

介绍

#GET请求
HTTP默认的请求方法就是GET
     * 没有请求体
     * 数据必须在1K之内!
     * GET请求数据会暴露在浏览器的地址栏中

GET请求常用的操作:
       1. 在浏览器的地址栏中直接给出URL,那么就一定是GET请求
       2. 点击页面上的超链接也一定是GET请求
       3. 提交表单时,表单默认使用GET请求,但可以设置为POST


#POST请求
(1). 数据不会出现在地址栏中
(2). 数据的大小没有上限
(3). 有请求体
(4). 请求体中如果存在中文,会使用URL编码!


#!!!requests.post()用法与requests.get()完全一致,特殊的是requests.post()有一个data参数,用来存放请求体数据

使用

# 1、基本POST实例

import requests

payload = {'key1': 'value1', 'key2': 'value2'}
ret = requests.post("http://httpbin.org/post", data=payload)  # data发送字典时发送的是urlencoding形式的数据

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)  # 此时data发送的json格式的数据

print(ret.text)
print(ret.cookies)  # 获取网站返回的cookie

发送post请求,模拟浏览器的登录行为

注意:
 1、对于登录来说,应该输错用户名或密码然后分析抓包流程,用脑子想一想,输对了浏览器就跳转了,还分析个毛线,累死你也找不到包

  2、要做登录的时候一定记得要把cookie先清除; 
  3、requests.session():中间的cookie都不用自己分析了,有用的没用的都给放进来了、
  4、response.cookie.get_dict()    #获取cookie

自动登录github

''' 一 目标站点分析
     浏览器输入https://github.com/login
     然后输入错误的账号密码,抓包
     发现登录行为是post提交到:https://github.com/session
     而且请求头包含cookie
     而且请求体包含:
         commit:Sign in
         utf8:✓
         authenticity_token:lbI8IJCwGslZS8qJPnof5e7ZkCoSoMn6jmDTsL1r/m06NLyIbw7vCrpwrFAPzHMep3Tmf/TSJVoXWrvDZaVwxQ==
         login:egonlin
         password:123
 
 
 二 流程分析
     先GET:https://github.com/login拿到初始cookie与authenticity_token
     返回POST:https://github.com/session, 带上初始cookie,带上请求体(authenticity_token,用户名,密码等)
     最后拿到登录cookie
 
     ps:如果密码时密文形式,则可以先输错账号,输对密码,然后到浏览器中拿到加密后的密码,github的密码是明文
 '''
 
import requests
import re
 #第一次请求
r1=requests.get('https://github.com/login')
r1_cookie=r1.cookies.get_dict() #拿到初始cookie(未被授权)
authenticity_token=re.findall(r'name="authenticity_token".*?value="(.*?)"',r1.text)[0] #从页面中拿到CSRF TOKEN

#第二次请求:带着初始cookie和TOKEN发送POST请求给登录页面,带上账号密码
data={
    'commit':'Sign in',
    'utf8':'',
    'authenticity_token':authenticity_token,
    'login':'317828332@qq.com',
    'password':'alex3714'
}
r2=requests.post('https://github.com/session',
             data=data,
             cookies=r1_cookie
             )


login_cookie=r2.cookies.get_dict()


#第三次请求:以后的登录,拿着login_cookie就可以,比如访问一些个人配置
r3=requests.get('https://github.com/settings/emails',
                cookies=login_cookie)

print('317828332@qq.com' in r3.text) #True

这里要注意先要使用get请求访问,获取一个未授权的cookie,发送post请求时要带着这个cookie,且这里用的form表单形式提交的,我们要到页面上找到token的内容并发送

import requests
import re

session = requests.session()
# 第一次请求
r1 = session.get('https://github.com/login')
authenticity_token = re.findall(r'name="authenticity_token".*?value="(.*?)"', r1.text)[0]  # 从页面中拿到CSRF TOKEN

# 第二次请求
data = {
    'commit': 'Sign in',
    'utf8': '',
    'authenticity_token': authenticity_token,
    'login': '317828332@qq.com',
    'password': 'alex3714'
}
r2 = session.post('https://github.com/session',
                  data=data,
                  )

# 第三次请求
r3 = session.get('https://github.com/settings/emails')

print('317828332@qq.com' in r3.text)  # True
requests.session()自动帮我们保存cookie信息

登录github小应用

import requests
import re
#第一次请求
    # GET请求
    # 请求头
    #    - 获取token和
    #    - User-agent
    #    - cookie
# 第二次请求
    #POST请求
    #请求头
        # referer
        # User-agent
    #请求体
        #获取data
# 第三次请求,登录成功之后
    #- 请求之前自己先登录一下,看一下有没有referer
    #- 请求新的url,进行其他操作
    #- 查看用户名在不在里面
#第一次请求
response1 = requests.get(
    "https://github.com/login",
    headers = {
        "User-Agent":"Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.108 Safari/537.36",
    },
)
authenticity_token = re.findall('name="authenticity_token".*?value="(.*?)"',response1.text,re.S)
r1_cookies =  response1.cookies.get_dict()
# print(r1_cookies,"cookie")  #获取到的cookie

#第二次请求
response2 = requests.post(
    "https://github.com/session",
    headers = {
        "Referer": "https://github.com/",
        "User-Agent":"Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.108 Safari/537.36",
    },
    data={
            "commit":"Sign in",
            "utf8":"",
            "authenticity_token":authenticity_token,
            "login":"haiyanzzz",
            "password":"xxxx",
zhy..azjash1234
    },
    cookies = r1_cookies
)
print(response2.status_code)
print(response2.history)  #跳转的历史状态码

#第三次请求,登录成功之后,访问其他页面
r2_cookies = response2.cookies.get_dict()  #拿上cookie,知道是你登录了,就开始访问页面
response3 = requests.get(
    "https://github.com/settings/emails",
    headers = {
        "Referer": "https://github.com/",
        "User-Agent": "Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.108 Safari/537.36",
    },
    cookies = r2_cookies,
)
print(response3.text)
print("haiyanzzz" in response3.text)   #True返回True说明就成功了

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)
参数示例

总结

requests 
    method: 请求方式
    url: 请求的url
    params: url中的参数?k1=v1&k2=v2
    data: 请求体的内容
    json: json格式的请求体的内容
    headers: 请求头
    cookies: 请求的cookie
    proxies: 封IP,用代理 
    
    
    
    files: 上传文件
    auth: 基本认证
    timeout: 超时时间
    allow_redirects: True 
    stream: 下载大文件时
        ret = requests.get('http://127.0.0.1:8000/test/', stream=True)
        for i in r.iter_content():
            # print(i)
        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)
                            
    cert: 证书
    verify: 确认

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。

下载

pip3 install beautifulsoup4

基本使用

soup = BeautifulSoup('<html>....</html>',"html.parser")

div = soup.find(name='标签名')  # 获取名字为name的标签对象
div = soup.find(name='标签名',id='i1')  # 获取名字为name,id为i1的标签对象
div = soup.find(name='div',attrs={'id':'auto-channel-lazyload-article','class':'id'})  # 其它属性可以通过attrs来设置

div.text 
div.attrs 
div.get('href')


divs = soup.find_all(name='标签名')
divs = soup.find_all(name='标签名',id='i1')
divs = soup.find_all(name='标签名',_class='i1')
divs = soup.find_all(name='div',attrs={'id':'auto-channel-lazyload-article','class':'id'})

divs是列表  # 列表中为一个个的标签对象
divs[0]

 

常见用法

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.descendants,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)

 

 

 

 

 

posted on 2018-05-07 19:19  Py行僧  阅读(195)  评论(0编辑  收藏  举报