python urllib库 python urllib库的使用详解
牛新龙的IT技术博客 人气:0相关:urllib是python内置的http请求库,本文介绍urllib三个模块:请求模块urllib.request、异常处理模块urllib.error、url解析模块urllib.parse。
1、请求模块:urllib.request
python2
import urllib2
response = urllib2.urlopen('http://httpbin.org/robots.txt')
python3
import urllib.request
res = urllib.request.urlopen('http://httpbin.org/robots.txt')
urllib.request.urlopen(url, data=None, [timeout, ]*, cafile=None, capath=None, cadefault=False, context=None)
urlopen()方法中的url参数可以是字符串,也可以是一个Request对象
#url可以是字符串 import urllib.request resp = urllib.request.urlopen('http://www.baidu.com') print(resp.read().decode('utf-8')) # read()获取响应体的内容,内容是bytes字节流,需要转换成字符串
##url可以也是Request对象 import urllib.request request = urllib.request.Request('http://httpbin.org') response = urllib.request.urlopen(request) print(response.read().decode('utf-8'))
data参数:post请求
# coding:utf8 import urllib.request, urllib.parse data = bytes(urllib.parse.urlencode({'word': 'hello'}), encoding='utf8') resp = urllib.request.urlopen('http://httpbin.org/post', data=data) print(resp.read())
urlopen()中的参数timeout:设置请求超时时间:
# coding:utf8 #设置请求超时时间 import urllib.request resp = urllib.request.urlopen('http://httpbin.org/get', timeout=0.1) print(resp.read().decode('utf-8'))
响应类型:
# coding:utf8 #响应类型 import urllib.request resp = urllib.request.urlopen('http://httpbin.org/get') print(type(resp))
响应的状态码、响应头:
# coding:utf8 #响应的状态码、响应头 import urllib.request resp = urllib.request.urlopen('http://www.baidu.com') print(resp.status) print(resp.getheaders()) # 数组(元组列表) print(resp.getheader('Server')) # "Server"大小写不区分
200
[('Bdpagetype', '1'), ('Bdqid', '0xa6d873bb003836ce'), ('Cache-Control', 'private'), ('Content-Type', 'text/html'), ('Cxy_all', 'baidu+b8704ff7c06fb8466a83df26d7f0ad23'), ('Date', 'Sun, 21 Apr 2019 15:18:24 GMT'), ('Expires', 'Sun, 21 Apr 2019 15:18:03 GMT'), ('P3p', 'CP=" OTI DSP COR IVA OUR IND COM "'), ('Server', 'BWS/1.1'), ('Set-Cookie', 'BAIDUID=8C61C3A67C1281B5952199E456EEC61E:FG=1; expires=Thu, 31-Dec-37 23:55:55 GMT; max-age=2147483647; path=/; domain=.baidu.com'), ('Set-Cookie', 'BIDUPSID=8C61C3A67C1281B5952199E456EEC61E; expires=Thu, 31-Dec-37 23:55:55 GMT; max-age=2147483647; path=/; domain=.baidu.com'), ('Set-Cookie', 'PSTM=1555859904; expires=Thu, 31-Dec-37 23:55:55 GMT; max-age=2147483647; path=/; domain=.baidu.com'), ('Set-Cookie', 'delPer=0; path=/; domain=.baidu.com'), ('Set-Cookie', 'BDSVRTM=0; path=/'), ('Set-Cookie', 'BD_HOME=0; path=/'), ('Set-Cookie', 'H_PS_PSSID=1452_28777_21078_28775_28722_28557_28838_28584_28604; path=/; domain=.baidu.com'), ('Vary', 'Accept-Encoding'), ('X-Ua-Compatible', 'IE=Edge,chrome=1'), ('Connection', 'close'), ('Transfer-Encoding', 'chunked')]
BWS/1.1
使用代理:urllib.request.ProxyHandler():
# coding:utf8 proxy_handler = urllib.request.ProxyHandler({'http': 'http://www.example.com:3128/'}) proxy_auth_handler = urllib.request.ProxyBasicAuthHandler() proxy_auth_handler.add_password('realm', 'host', 'username', 'password') opener = urllib.request.build_opener(proxy_handler, proxy_auth_handler) # This time, rather than install the OpenerDirector, we use it directly: resp = opener.open('http://www.example.com/login.html') print(resp.read())
2、异常处理模块:urllib.error
异常处理实例1:
# coding:utf8 from urllib import error, request try: resp = request.urlopen('http://www.blueflags.cn') except error.URLError as e: print(e.reason)
异常处理实例2:
# coding:utf8 from urllib import error, request try: resp = request.urlopen('http://www.baidu.com') 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')
异常处理实例3:
# coding:utf8 import socket, urllib.request, urllib.error try: resp = urllib.request.urlopen('http://www.baidu.com', timeout=0.01) except urllib.error.URLError as e: print(type(e.reason)) if isinstance(e.reason,socket.timeout): print('time out')
3、url解析模块:urllib.parse
parse.urlencode
# coding:utf8 from urllib import request, parse url = 'http://httpbin.org/post' headers = { 'Host': 'httpbin.org', 'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/72.0.3626.109 Safari/537.36' } dict = {'name': 'Germey'} data = bytes(parse.urlencode(dict), encoding='utf8') req = request.Request(url=url, data=data, headers=headers, method='POST') resp = request.urlopen(req) print(resp.read().decode('utf-8'))
{ "args": {}, "data": "", "files": {}, "form": { "name": "Thanlon" }, "headers": { "Accept-Encoding": "identity", "Content-Length": "12", "Content-Type": "application/x-www-form-urlencoded", "Host": "httpbin.org", "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/72.0.3626.109 Safari/537.36" }, "json": null, "origin": "117.136.78.194, 117.136.78.194", "url": "https://httpbin.org/post" }
add_header方法添加请求头:
# coding:utf8 from urllib import request, parse url = 'http://httpbin.org/post' dict = {'name': 'Thanlon'} data = bytes(parse.urlencode(dict), encoding='utf8') req = request.Request(url=url, data=data, method='POST') req.add_header('User-Agent', 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/72.0.3626.109 Safari/537.36') resp = request.urlopen(req) print(resp.read().decode('utf-8'))
parse.urlparse:
# coding:utf8 from urllib.parse import urlparse result = urlparse('http://www.baidu.com/index.html;user?id=1#comment') print(type(result)) print(result)
<class 'urllib.parse.ParseResult'>
ParseResult(scheme='http', netloc='www.baidu.com', path='/index.html', params='user', query='id=1', fragment='comment')
from urllib.parse import urlparse result = urlparse('www.baidu.com/index.html;user?id=1#comment', scheme='https') print(type(result)) print(result)
<class 'urllib.parse.ParseResult'>
ParseResult(scheme='https', netloc='', path='www.baidu.com/index.html', params='user', query='id=1', fragment='comment')
# coding:utf8 from urllib.parse import urlparse result = urlparse('http://www.baidu.com/index.html;user?id=1#comment', scheme='https') print(result)
ParseResult(scheme='http', netloc='www.baidu.com', path='/index.html', params='user', query='id=1', fragment='comment')
# coding:utf8 from urllib.parse import urlparse result = urlparse('http://www.baidu.com/index.html;user?id=1#comment',allow_fragments=False) print(result)
ParseResult(scheme='http', netloc='www.baidu.com', path='/index.html', params='user', query='id=1', fragment='comment')
parse.urlunparse:
# coding:utf8 from urllib.parse import urlunparse data = ['http', 'www.baidu.com', 'index.html', 'user', 'name=Thanlon', 'comment'] print(urlunparse(data))
parse.urljoin:
# coding:utf8 from urllib.parse import urljoin print(urljoin('http://www.bai.com', 'index.html')) print(urljoin('http://www.baicu.com', 'https://www.thanlon.cn/index.html'))#以后面为基准
urlencode将字典对象转换成get请求的参数:
# coding:utf8 from urllib.parse import urlencode params = { 'name': 'Thanlon', 'age': 22 } baseUrl = 'http://www.thanlon.cn?' url = baseUrl + urlencode(params) print(url)
4、Cookie
cookie的获取(保持登录会话信息):
# coding:utf8 #cookie的获取(保持登录会话信息) import urllib.request, http.cookiejar cookie = http.cookiejar.CookieJar() handler = urllib.request.HTTPCookieProcessor(cookie) opener = urllib.request.build_opener(handler) res = opener.open('http://www.baidu.com') for item in cookie: print(item.name + '=' + item.value)
MozillaCookieJar(filename)形式保存cookie
# coding:utf8 #将cookie保存为cookie.txt import http.cookiejar, urllib.request filename = 'cookie.txt' cookie = http.cookiejar.MozillaCookieJar(filename) handler = urllib.request.HTTPCookieProcessor(cookie) opener = urllib.request.build_opener(handler) res = opener.open('http://www.baidu.com') cookie.save(ignore_discard=True, ignore_expires=True)
LWPCookieJar(filename)形式保存cookie:
# coding:utf8 import http.cookiejar, urllib.request filename = 'cookie.txt' cookie = http.cookiejar.LWPCookieJar(filename) handler = urllib.request.HTTPCookieProcessor(cookie) opener = urllib.request.build_opener(handler) res = opener.open('http://www.baidu.com') cookie.save(ignore_discard=True, ignore_expires=True)
读取cookie请求,获取登陆后的信息
# coding:utf8 import http.cookiejar, urllib.request 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) resp = opener.open('http://www.baidu.com') print(resp.read().decode('utf-8'))
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