python自动化开发-[第二十三天]-初识爬虫
今日概要：
1、爬汽车之家的新闻资讯
2、爬github和chouti
3、requests和beautifulsoup
4、轮询和长轮询
5、django request.POST和request.body
一、HTTP知识扫盲
1、http的get请求 是没有请求体,所有的参数都放在请求头的url里
2、http的post请求 将请求内容放到请求体里
3、http = 请求头+请求体 响应头+响应体
4、http是无状态请求,一个请求，一次响应就会结束
二、爬取汽车之家的新闻页
#!/usr/bin/python
# -*- coding:utf-8 -*-
import requests
from bs4 import BeautifulSoup
response = requests.get('http://www.autohome.com.cn/news')
response.encoding = 'gbk' #汽车之家的中文是gbk编码
# print(response.text)
soup = BeautifulSoup(response.text,'html.parser')
tag = soup.find(name='div',attrs={'id':'auto-channel-lazyload-article'})
li_list = tag.find_all('li')
for li in li_list:
if li.find(name='h3'):
print(li.find(name='h3').text)
2.1爬取鲜花网
import requests
from bs4 import BeautifulSoup
response = requests.get('http://www.hua.com/aiqingxianhua/')
root = BeautifulSoup(response.text,'html.parser') #实例化soup对象
#通过.进行查找,所有的标签都为对象
div_list = root.find_all(attrs={"class":"grid-item"})
for div in div_list:
img_dir = div.find(name='img').get('src')
title = div.find(name='span',attrs={"class":"product-title"})
price = div.find(name='span',attrs={"class":"price-num"})
print(img_dir,title.text,price.text)
'''
//img01.hua.com/uploadpic/newpic/9012247.jpg_220x240.jpg 鲜花/幸福的约定-苏醒玫瑰33枝、紫罗兰、银叶菊 339
//img01.hua.com/uploadpic/newpic/9012246.jpg_220x240.jpg 鲜花/邻家女孩-红玫瑰33枝、红色小雏菊 296
//img01.hua.com/uploadpic/newpic/9010011.jpg_220x240.jpg 鲜花/一心一意-玫瑰11枝，粉色勿忘我0.3扎 126
//img01.hua.com/uploadpic/newpic/9012011.jpg_220x240.jpg 鲜花/阳光海岸-19枝香槟玫瑰 218
//img01.hua.com/uploadpic/newpic/9010966.jpg_220x240.jpg 鲜花/一往情深-精品玫瑰礼盒:19枝红玫瑰，勿忘我适量 235
//img01.hua.com/uploadpic/newpic/9012042.jpg_220x240.jpg 鲜花/热恋-红玫瑰50枝 359
//img01.hua.com/uploadpic/newpic/9012041.jpg_220x240.jpg 鲜花/浪漫缤纷-戴安娜粉玫瑰50枝 359
//img01.hua.com/uploadpic/newpic/9012175.jpg_220x240.jpg 鲜花/月光女神-白玫瑰11枝，绿色桔梗5枝，小菊3枝，白色石竹梅4枝 228
//img01.hua.com/uploadpic/newpic/9010947.jpg_220x240.jpg 鲜花/真爱如初-雪山玫瑰11枝、深紫色勿忘我0.3扎 186
//img01.hua.com/uploadpic/newpic/9012177.jpg_220x240.jpg 鲜花/不变的承诺-99枝红玫瑰 519
'''
三、爬取gitlab和chouti的新闻页
github自动登录
#!/usr/bin/python
# -*- coding:utf-8 -*-
import requests
from bs4 import BeautifulSoup
r1 = requests.get(url='https://github.com/login')
b1 = BeautifulSoup(r1.text,'html.parser')
auth_token = b1.find(attrs={'name':'authenticity_token'}).get('value')
r1_cookies_data = r1.cookies.get_dict()
print(auth_token)
r2 = requests.post('https://github.com/session', data={
"commit": "Sign in",
"utf8": '✓',
"authenticity_token": auth_token,
"login": "xxxx",
"password": "xxxx",
},
cookies=r1_cookies_data)
r2_cookies_data = r2.cookies.get_dict()
print(r1_cookies_data)
print(r2_cookies_data)
all_cookies = {}
all_cookies.update(r1_cookies_data)
all_cookies.update(r2_cookies_data)
#github直接用带token之后的cookies就行
r3 = requests.get('https://github.com/settings/emails',cookies=r2_cookies_data)
print(r3.text)
登录抽屉并自动点赞
#!/usr/bin/python
# -*- coding:utf-8 -*-
import requests
r1 = requests.get(url='http://dig.chouti.com/')
r1_cookies_data = r1.cookies.get_dict()
r2 = requests.post('http://dig.chouti.com/login',data={'phone':'xxx',"password":"xxx","oneMonth":1}
,cookies=r1_cookies_data)
r2_cookies_data = r2.cookies.get_dict()
print(r1_cookies_data)
print(r2_cookies_data)
all_cookies = {}
all_cookies.update(r1_cookies_data)
all_cookies.update(r2_cookies_data)
'''
session_id 在第一次请求
{'JSESSIONID': 'aaaIZQdBA4siraQ2m0t8v', 'route': '0c5178ac241ad1c9437c2aafd89a0e50', 'gpsd': 'dd55c4cda0a45f6bc3274a79a7e50316'}
{'puid': '417d102e3c72e88cd6003bc984c569b4', 'gpid': '4c91ec17bd8340bdb75116916e19bc20'}
'''
r3 = requests.post('http://dig.chouti.com/link/vote?linksId=14708906',cookies=r1_cookies_data)
print(r3.text)
'''
{"result":{"code":"9999", "message":"推荐成功", "data":{"jid":"cdu_50096919787","likedTime":"1508043437615000","lvCount":"6","nick":"congratula","uvCount":"3","voteTime":"小于1分钟前"}}}
'''
注意:有的登录页面,登录的时候不一定会给cookie,需要get一次才给cookie,而登录的时候仅仅是授权,get的时候的cookie,这样就不需要带第二次的cookie去请求
四、轮询和长轮询
-
轮询：客户端定时向服务器发送Ajax请求，服务器接到请求后马上返回响应信息并关闭连接。
优点：后端程序编写比较容易。
缺点：请求中有大半是无用，浪费带宽和服务器资源。
实例：适于小型应用。 -
长轮询：客户端向服务器发送Ajax请求，服务器接到请求后hold住连接，直到有新消息才返回响应信息并关闭连接，客户端处理完响应信息后再向服务器发送新的请求，服务器端会设置超时时间,当出现超时的时候，服务端会断开链接，客户端会再次请求服务端hold住
优点：在无消息的情况下不会频繁的请求。
缺点：服务器hold连接会消耗资源。
实例：WebQQ、Hi网页版、Facebook IM。
另外，对于长连接和socket连接也有区分：
-
长连接：在页面里嵌入一个隐蔵iframe，将这个隐蔵iframe的src属性设为对一个长连接的请求，服务器端就能源源不断地往客户端输入数据。
优点：消息即时到达，不发无用请求。
缺点：服务器维护一个长连接会增加开销。
实例：Gmail聊天
五、requests的用法
1、GET请求：
requests.get(url="http://www.oldboyedu.com")
# data="http GET / http1.1\r\nhost:oldboyedu.com\r\n....\r\n\r\n"
requests.get(url="http://www.oldboyedu.com/index.html?p=1")
# data="http GET /index.html?p=1 http1.1\r\nhost:oldboyedu.com\r\n....\r\n\r\n"
requests.get(url="http://www.oldboyedu.com/index.html",params={'p':1})
# data="http GET /index.html?p=1 http1.1\r\nhost:oldboyedu.com\r\n....\r\n\r\n"
2、POST请求：
requests.post(url="http://www.oldboyedu.com",data={'name':'alex','age':18}) # 默认请求头：application/x-www-form-urlencoded
data="http POST / http1.1\r\nhost:oldboyedu.com\r\n....\r\n\r\nname=alex&age=18"
requests.post(url="http://www.oldboyedu.com",json={'name':'alex','age':18}) # 默认请求头：application/json
data="http POST / http1.1\r\nhost:oldboyedu.com\r\n....\r\n\r\n{"name": "alex", "age": 18}"
requests.post(
url="http://www.oldboyedu.com",
params={'p':1},
json={'name':'alex','age':18}
) # 默认请求头：application/json
data="http POST /?p=1 http1.1\r\nhost:oldboyedu.com\r\n....\r\n\r\n{"name": "alex", "age": 18}"
3、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
verify一般和cert合着用
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'))
# } #元祖里套元祖
# 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
#一些非form表单，浏览器自带的认证框,它们都是通过固定的算法得出来的,可以用这个去认证
#r.headers['Authorization'] = _basic_auth_str(self.username, self.password) 查看源码
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():
# 设置超时时间
# ret = requests.get('http://google.com/', timeout=1)
# print(ret)
# 设置超时时间和断开时间
# ret = requests.get('http://google.com/', timeout=(5, 1))
# print(ret)
pass
def param_allow_redirects():
#比如访问一个网站redirect另外一个地址,这次http请求是有返回值的,allow_redirects可以设置是否跳转到新的地址,重新发请求
ret = requests.get('http://127.0.0.1:8000/test/', allow_redirects=False)
print(ret.text)
def param_proxies():
# 设置代理,可以设置很多
# 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
# 设置需要认证的代理
#
# 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():
#将一个大的数据比如30g,进行分段传输
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():
#建议刚开始 别使用,能记录cookie等内容 不必每次都去 取
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)
六、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。
soup = BeautifulSoup(html_doc, features="lxml") #会以xml格式解析,需要额外安装lxml，比html.parser节省资源
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 结果是一个集合 # 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,(自己也会删除)
# 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(类似于dict里的pop)
# 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） (将标签对象转换为格式)
# 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 class是类变量 可以用class_ 去代替
# 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
html_doc = """ <html><head><title>The Dormouse's story</title></head> <body> <a id='a1'>123</a> </body> </html> """ soup = BeautifulSoup(html_doc, features="lxml") 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
#from bs4.element import Tag # soup.next #查该标签内部子代 # soup.next_element # soup.next_elements #递归查找子代 # soup.next_sibling # soup.next_siblings #只查下面的 # # tag.previous #查标签外部 # tag.previous_element # tag.previous_elements # tag.previous_sibling #查兄弟标签 # tag.previous_siblings #只向上查找 # # tag.parent #查父亲 # tag.parents
17. 查找某标签的关联标签
# tag.find_next(...) #可以加条件筛选 # 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)
string和text的区别:
1.string 可以赋值，text不可以
2.string 这个类型<class 'bs4.element.NavigableString'> text是这个类型 <class 'str'>
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(非常规思维,创建的关系在soup里是无法看到的)
# 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)
爬取知乎：
