Python之爬虫
网络爬虫(又被称为网页蜘蛛,网络机器人,在FOAF社区中间,更经常的称为网页追逐者),是一种按照一定的规则,自动地抓取万维网信息的程序或者脚本。另外一些不常使用的名字还有蚂蚁、自动索引、模拟程序或者蠕虫。
关于Python的爬虫框架Scrapy
请移步至这篇博文——>>> Python爬虫框架——Scrapy
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。
1、GET请求
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# 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
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# 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、其它请求
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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]> """
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。
# 安装 pip3 install beautifulsoup4
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')
1,name,标签名称
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tag = soup.find( 'a' ) name = tag.name # 获取 print (name) tag.name = 'span' # 设置 print (soup) |
2,attr,标签属性
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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
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body = soup.find( 'body' ) v = body.children |
4,descendants,所有子子孙孙标签
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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)
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tag = soup.find( 'body' ) tag.clear() print (soup) |
6,decompose,递归的删除所有的标签
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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
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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)
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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)
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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
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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
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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
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tag = soup.find( 'a' ) v = tag.has_attr( 'id' ) print (v) |
13,get_text,获取标签内部文本内容
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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
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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'
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tag = soup.find( 'br' ) v = tag.is_empty_element print (v) |
16,当前的关联标签
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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tag = soup.find( 'a' ) v = tag.unwrap() print (soup) |
更多参数官方:http://beautifulsoup.readthedocs.io/zh_CN/v4.4.0/
"破解"微信公众号
根据Django和Requests分析破解微信公众号
"破解"微信公众号其实就是使用Python代码自动实现【扫码登陆个人微信】->【获取个人所有联系人】-> 【向某联系人或群组或公众号发送消息】。如下图
那么,是如何登陆获取联系人的呢???
代码及解释请移步——>>> https://github.com/bingdujianer/WebWeChat