python urllib和urllib3包
Posted qiuri2008
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urllib.request
urllib当中使用最多的模块,涉及请求,响应,浏览器模拟,代理,cookie等功能。
request.urlopen(url, data=None, timeout=10) #url: 需要打开的网址 #data:Post提交的数据 #timeout:设置网站的访问超时时间 from urllib import request import ssl # 解决某些环境下报<urlopen error [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed ssl._create_default_https_context = ssl._create_unverified_context url = \'https://www.jianshu.com\' #返回<http.client.HTTPResponse object at 0x0000000002E34550> response = request.urlopen(url, data=None, timeout=10) #直接用urllib.request模块的urlopen()获取页面,page的数据格式为bytes类型,需要decode()解码,转换成str类型。 page = response.read().decode(\'utf-8\')
需要添加headers头信息,urlopen不支持,需要使用Request
PC
import urllib.request url = \'https://www.jianshu.com\' # 增加header headers = { \'User-Agent\': \'Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.96 Safari/537.36\' } request = urllib.request.Request(url,headers=headers) response = urllib.request.urlopen(request) #在urllib里面 判断是get请求还是post请求,就是判断是否提交了data参数 print(request.get_method()) >> 输出结果 GET
req = request.Request(\'http://www.douban.com/\') req.add_header(\'User-Agent\', \'Mozilla/6.0 (iPhone; CPU iPhone OS 8_0 like Mac OS X) \' \'AppleWebKit/536.26 (KHTML, like Gecko) Version/8.0 Mobile/10A5376e Safari/8536.25\') with request.urlopen(req) as f: print(\'Status:\', f.status, f.reason) for k, v in f.getheaders(): print(\'%s: %s\' % (k, v)) print(\'Data:\', f.read().decode(\'utf-8\'))
客户端用于记录用户身份,维持登录信息
import http.cookiejar, urllib.request # 1 创建CookieJar对象 cookie = http.cookiejar.CookieJar() # 使用HTTPCookieProcessor创建cookie处理器, handler = urllib.request.HTTPCookieProcessor(cookie) # 构建opener对象 opener = urllib.request.build_opener(handler) # 将opener安装为全局 urllib.request.install_opener(opener) data = urllib.request.urlopen(url) # 2 保存cookie为文本 import http.cookiejar, urllib.request filename = "cookie.txt" # 保存类型有很多种 ## 类型1 cookie = http.cookiejar.MozillaCookieJar(filename) ## 类型2 cookie = http.cookiejar.LWPCookieJar(filename) # 使用相应的方法读取 cookie = http.cookiejar.LWPCookieJar() cookie.load(\'cookie.txt\',ignore_discard=True,ignore_expires=True) handler = urllib.request.HTTPCookieProcessor(cookie) opener = urllib.request.build_opener(handler) ……
4.设置代理
当需要抓取的网站设置了访问限制,这时就需要用到代理来抓取数据。
import urllib.request url = \'http://httpbin.org/ip\' proxy = {\'http\':\'39.134.108.89:8080\',\'https\':\'39.134.108.89:8080\'} proxies = urllib.request.ProxyHandler(proxy) # 创建代理处理器 opener = urllib.request.build_opener(proxies,urllib.request.HTTPHandler) # 创建特定的opener对象 urllib.request.install_opener(opener) # 安装全局的opener 把urlopen也变成特定的opener data = urllib.request.urlopen(url) print(data.read().decode())
import urllib.error import urllib.request requset = urllib.request.Request(\'http://www.usahfkjashfj.com/\') try: urllib.request.urlopen(requset).read() except urllib.error.URLError as e: print(e.reason) else: print(\'success\') >> print结果 [Errno 11004] getaddrinfo failed
HTTPError是URLError的子类,在你利用URLopen方法发出一个请求时,服务器上都会对应一个应答对象response,其中他包含一个数字“状态码”,
例如response是一个重定向,需定位到别的地址获取文档,urllib将对此进行处理。其他不能处理的,URLopen会产生一个HTTPError,对应相应的状态码,
HTTP状态码表示HTTP协议所返回的响应的状态。
from urllib import request, error try: response = request.urlopen(\'http://cuiqingcai.com/index.htm\') except error.URLError as e: print(e.reason) # 先捕获子类错误 try: response = request.urlopen(\'http://cuiqingcai.com/index.htm\') except error.HTTPError as e: print(e.reason, e.code, e.headers, sep=\'\\n\') except error.URLError as e: print(e.reason) else: print(\'Request Successfully\')
>> print结果
Not Found
-------------
Not Found
404
Server: nginx/1.10.3 (Ubuntu)
Date: Thu, 08 Feb 2018 14:45:39 GMT
Content-Type: text/html; charset=UTF-8
Transfer-Encoding: chunked
Connection: close
Vary: Cookie
Expires: Wed, 11 Jan 1984 05:00:00 GMT
print(parse.urljoin(\'https://www.jianshu.com/xyz\',\'FAQ.html\')) print(parse.urljoin(\'http://www.baidu.com/about.html\',\'http://www.baidu.com/FAQ.html\')) >>结果 https://www.jianshu.com/FAQ.html http://www.baidu.com/FAQ.html
urllib.parse.urlencode 字典转字符串
from urllib import request, parse url = r\'https://www.jianshu.com/collections/20f7f4031550/mark_viewed.json\' headers = { \'User-Agent\': r\'Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.132 Safari/537.36\', \'Referer\': r\'https://www.jianshu.com/c/20f7f4031550?utm_medium=index-collections&utm_source=desktop\', \'Connection\': \'keep-alive\' } data = { \'uuid\': \'5a9a30b5-3259-4fa0-ab1f-be647dbeb08a\', } #Post的数据必须是bytes或者iterable of bytes,不能是str,因此需要进行encode()编码 data = parse.urlencode(data).encode(\'utf-8\') print(data) req = request.Request(url, headers=headers, data=data) page = request.urlopen(req).read() page = page.decode(\'utf-8\') print(page) >>结果 b\'uuid=5a9a30b5-3259-4fa0-ab1f-be647dbeb08a\' {"message":"success"}
urllib.parse.quote url编码
urllib.parse.unquote url解码
Url的编码格式采用的是ASCII码,而不是Unicode,比如
http://so.biquge.la/cse/search?s=7138806708853866527&q=%CD%EA%C3%C0%CA%C0%BD%E7
from urllib import parse x = parse.quote(\'山西\', encoding=\'gb18030\')# encoding=\'GBK print(x) #%C9%BD%CE%F7 city = parse.unquote(\'%E5%B1%B1%E8%A5%BF\',) # encoding=\'utf-8\' print(city) # 山西
urllib3包
Urllib3是一个功能强大,条理清晰,用于HTTP客户端的Python库,许多Python的原生系统已经开始使用urllib3。Urllib3提供了很多python标准库里所没有的重要特性:
1.线程安全
2.连接池
3.客户端SSL/TLS验证
4.文件分部编码上传
5.协助处理重复请求和HTTP重定位
6.支持压缩编码
7.支持HTTP和SOCKS代理
安装:
Urllib3 能通过pip来安装:
$pip install urllib3
你也可以在github上下载最新的源码,解压之后进行安装:
$git clone git://github.com/shazow/urllib3.git
$python setup.py install
urllib3的使用:
request GET请求
import urllib3 import requests # 忽略警告:InsecureRequestWarning: Unverified HTTPS request is being made. Adding certificate verification is strongly advised. requests.packages.urllib3.disable_warnings() # 一个PoolManager实例来生成请求, 由该实例对象处理与线程池的连接以及线程安全的所有细节 http = urllib3.PoolManager() # 通过request()方法创建一个请求: r = http.request(\'GET\', \'http://cuiqingcai.com/\') print(r.status) # 200 # 获得html源码,utf-8解码 print(r.data.decode())
request GET请求(添加数据)
header = { \'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\' } r = http.request(\'GET\', \'https://www.baidu.com/s?\', fields={\'wd\': \'hello\'}, headers=header) print(r.status) # 200 print(r.data.decode())
post请求
#你还可以通过request()方法向请求(request)中添加一些其他信息,如: header = { \'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\' } r = http.request(\'POST\', \'http://httpbin.org/post\', fields={\'hello\':\'world\'}, headers=header) print(r.data.decode())
# 对于POST和PUT请求(request),需要手动对传入数据进行编码,然后加在URL之后: encode_arg = urllib.parse.urlencode({\'arg\': \'我的\'}) print(encode_arg.encode()) r = http.request(\'POST\', \'http://httpbin.org/post?\'+encode_arg, headers=header) # unicode解码 print(r.data.decode(\'unicode_escape\'))
发送json数据
#JSON:在发起请求时,可以通过定义body 参数并定义headers的Content-Type参数来发送一个已经过编译的JSON数据: import json data={\'attribute\':\'value\'} encode_data= json.dumps(data).encode() r = http.request(\'POST\', \'http://httpbin.org/post\', body=encode_data, headers={\'Content-Type\':\'application/json\'} ) print(r.data.decode(\'unicode_escape\'))
上传文件
#使用multipart/form-data编码方式上传文件,可以使用和传入Form data数据一样的方法进行,并将文件定义为一个元组的形式 (file_name,file_data): with open(\'1.txt\',\'r+\',encoding=\'UTF-8\') as f: file_read = f.read() r = http.request(\'POST\', \'http://httpbin.org/post\', fields={\'filefield\':(\'1.txt\', file_read, \'text/plain\') }) print(r.data.decode(\'unicode_escape\')) #二进制文件 with open(\'websocket.jpg\',\'rb\') as f2: binary_read = f2.read() r = http.request(\'POST\', \'http://httpbin.org/post\', body=binary_read, headers={\'Content-Type\': \'image/jpeg\'}) # # print(json.loads(r.data.decode(\'utf-8\'))[\'data\'] ) print(r.data.decode(\'utf-8\'))
使用Timeout
#使用timeout,可以控制请求的运行时间。在一些简单的应用中,可以将timeout参数设置为一个浮点数: r = http.request(\'POST\', \'http://httpbin.org/post\',timeout=3.0) print(r.data.decode(\'utf-8\')) #让所有的request都遵循一个timeout,可以将timeout参数定义在PoolManager中: http = urllib3.PoolManager(timeout=3.0)
对重试和重定向进行控制
#通过设置retries参数对重试进行控制。Urllib3默认进行3次请求重试,并进行3次方向改变。 r = http.request(\'GET\', \'http://httpbin.org/ip\',retries=5)#请求重试的次数为5 print(r.data.decode(\'utf-8\')) ##关闭请求重试(retrying request)及重定向(redirect)只要将retries定义为False即可: r = http.request(\'GET\', \'http://httpbin.org/redirect/1\',retries=False,redirect=False) print(\'d1\',r.data.decode(\'utf-8\')) #关闭重定向(redirect)但保持重试(retrying request),将redirect参数定义为False即可 r = http.request(\'GET\', \'http://httpbin.org/redirect/1\',redirect=False)
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