1、urllib模块
1.urllib.urlopen(url[,data[,proxies]])
打开一个url的方法,返回一个文件对象,然后可以进行类似文件对象的操作。本例试着打开google
import urllibf = urllib.urlopen('http://www.google.com.hk/')firstLine = f.readline() #读取html页面的第一行
urlopen返回对象提供方法:
- read([bytes]):读所以字节或者bytes个字节
- readline():读一行
- readlines() :读所有行
- fileno() :返回文件句柄
- close() :关闭url链接
- info():返回一个httplib.HTTPMessage对象,表示远程服务器返回的头信息
- getcode():返回Http状态码。如果是http请求,200请求成功完成;404网址未找到
- geturl():返回请求的url
2.urllib.urlretrieve(url[,filename[,reporthook[,data]]])
urlretrieve方法将url定位到的html文件下载到你本地的硬盘中。如果不指定filename,则会存为临时文件。
urlretrieve()返回一个二元组(filename,mine_hdrs)
临时存放:
filename = urllib.urlretrieve('http://www.google.com.hk/')type(filename)print filename[0]print filename[1]
输出:
'/tmp/tmp8eVLjq'
存为本地文件:
filename = urllib.urlretrieve('http://www.baidu.com/',filename='/home/dzhwen/python文件/Homework/urllib/google.html')print type(filename)print filename[0]print filename[1]
输出:
'/home/dzhwen/python\xe6\x96\x87\xe4\xbb\xb6/Homework/urllib/google.html'
reporthook参数使用如下:
def process(blk,blk_size,total_size): print('%d/%d - %.02f%%' %(blk*blk_size,total_size,(float)(blk * blk_size) / total_size * 100))def download(): filename,fileinfo = urllib.urlretrieve('http://cnblogs.com','index.html',reporthook=process)
输出结果:
0/46164 - 0.00%8192/46164 - 17.75%16384/46164 - 35.49%24576/46164 - 53.24%32768/46164 - 70.98%40960/46164 - 88.73%49152/46164 - 106.47%
blk * blk_size的有可能超过total_size,如上函数可以改写为:
def process(blk,blk_size,total_size): if total_size == -1: print "can't determine the file size, now retrived", blk * blk_size else: percentage = int((blk * blk_size * 100.0) / total_size) if percentage >= 100: print('%d/%d - %d%%' % (total_size, total_size, 100)) else: print('%d/%d - %d%%' % (blk * blk_size, total_size, percentage))
运行后输出:
0/46238 - 0%8192/46238 - 17%16384/46238 - 35%24576/46238 - 53%32768/46238 - 70%40960/46238 - 88%46238/46238 - 100%
3.urllib.urlcleanup()
清除由于urllib.urlretrieve()所产生的缓存
4.urllib.quote(url)和urllib.quote_plus(url)
将url数据获取之后,并将其编码,从而适用与URL字符串中,使其能被打印和被web服务器接受。
urllib.quote('http://www.baidu.com')
转换结果:
'http%3A//www.baidu.com'
urllib.quote_plus('http://www.baidu.com')
转换结果:
'http%3A%2F%2Fwww.baidu.com'
5.urllib.unquote(url)和urllib.unquote_plus(url)
与4的函数相反。
6.urllib.urlencode(query)
将URL中的键值对以连接符&划分
这里可以与urlopen结合以实现post方法和get方法:
GET方法:
import urllibparams=urllib.urlencode({'spam':1,'eggs':2,'bacon':0})f=urllib.urlopen("http://python.org/query?%s" % params)print f.read()
POST方法:
import urllibparmas = urllib.urlencode({'spam':1,'eggs':2,'bacon':0})f=urllib.urlopen("http://python.org/query",parmas)f.read()
2.urlparse模块
1.urlparse
作用:反向解析url
def parse_html(): url = 'https://www.baidu.com/s?wd=python&rsv_spt=1&rsv_iqid=0xad2dc5550032146a&issp=1&f=8&rsv_bp=0&rsv_idx=2&ie=utf-8&tn=baiduhome_pg&rsv_enter=1&rsv_sug3=7&rsv_sug1=5&rsv_sug7=100&rsv_sug2=0&inputT=22&rsv_sug4=4980' result = urlparse.urlparse(url) # params = urlparse.parse_qs(result.query) print result # print params
运行结果:
ParseResult(scheme='https', netloc='www.baidu.com', path='/s', params='', query='wd=python&rsv_spt=1&rsv_iqid=0xad2dc5550032146a&issp=1&f=8&rsv_bp=0&rsv_idx=2&ie=utf-8&tn=baiduhome_pg&rsv_enter=1&rsv_sug3=7&rsv_sug1=5&rsv_sug7=100&rsv_sug2=0&inputT=22&rsv_sug4=4980', fragment='')
如上返回的是一个parseResult对象,其中包括协议类型、主机地址、路径、参数以及query
2.parse_qs
import urllibimport urlparsedef parse_html(): url = 'https://www.baidu.com/s?wd=python&rsv_spt=1&rsv_iqid=0xad2dc5550032146a&issp=1&f=8&rsv_bp=0&rsv_idx=2&ie=utf-8&tn=baiduhome_pg&rsv_enter=1&rsv_sug3=7&rsv_sug1=5&rsv_sug7=100&rsv_sug2=0&inputT=22&rsv_sug4=4980' result = urlparse.urlparse(url) params = urlparse.parse_qs(result.query) # print result print paramsif __name__ == '__main__': # demo() # demo2() parse_html()
运行结果:
{'wd': ['python'], 'rsv_spt': ['1'], 'rsv_iqid': ['0xad2dc5550032146a'], 'inputT': ['22'], 'f': ['8'], 'rsv_enter': ['1'], 'rsv_bp': ['0'], 'rsv_idx': ['2'], 'tn': ['baiduhome_pg'], 'rsv_sug4': ['4980'], 'rsv_sug7': ['100'], 'rsv_sug1': ['5'], 'issp': ['1'], 'rsv_sug3': ['7'], 'rsv_sug2': ['0'], 'ie': ['utf-8']}
3、urllib2模块
urllib2提供更加强大的功能,如cookie的管理,但并不能完全代替urllib,因为urllib.urlencode函数urllib2中是没有的
3.1 urllib2.urlopen()
作用:打开url
参数:
- url
- data = None
- timeout = <object>
import urllibimport urllib2def demo(): url = 'http://www.cnblogs.com/hester/sllsl' try: s = urllib2.urlopen(url,timeout = 3) except urllib2.HTTPError,e: print e else: print s.read(100)if __name__ == '__main__': demo()
运行结果:
”温故而知新“
如果url更改为未知的网址:
url = 'http://www.cnblogs.com/hester/asdfas'
运行结果:
HTTP Error 404: Not Found
3.2 urllib2.Request()
作用:添加或者修改http头
参数:
- url
- data
- headers
import urllibimport urllib2def demo(): url = 'http://www.cnblogs.com/hester' headers = {'User-Agent':'Mozilla/5.0','x-my-hester':'my value'} req = urllib2.Request(url,headers=headers) s = urllib2.urlopen(req) print s.read(100) print req.headers s.close()if __name__ == '__main__': demo()
运行结果:
”温故而知新“ {'X-my-hester': 'my value', 'User-agent': 'Mozilla/5.0'}
3.3 urllib2.bulid_opener()
作用:创建一个打开器
参数:
- Handler列表
- ProxyHandler
- UnknownHandler
- HTTPHandler
- HTTPDefaultHandler
- HTTPRedirectHandler
- FTPHandler
- FileHandler
- HTTPErrorHandler
- HTTPSHandler
返回:
- OpenerDirector
import urllibimport urllib2def request_post_debug(): data = {'username':'hester_ge','password':'xxxxxxx'} headers = {'User-Agent':'Mozilla/5.0','x-my-hester':'my value'} req = urllib2.Request('http://www.cnblogs.com/hester',data = urllib.urlencode(data),headers=headers) opener = urllib2.build_opener(urllib2.HTTPHandler(debuglevel=1)) s = opener.open(req) print s.read(100) s.close()if __name__ == '__main__': request_post_debug()
运行结果:
send: 'POST /hester HTTP/1.1\r\nAccept-Encoding: identity\r\nContent-Length: 35\r\nHost: www.cnblogs.com\r\nX-My-Hester: my value\r\nUser-Agent: Mozilla/5.0\r\nConnection: close\r\nContent-Type: application/x-www-form-urlencoded\r\n\r\nusername=hester_ge&password=xxxxxxx'reply: 'HTTP/1.1 200 OK\r\n'header: Date: Sun, 03 Jul 2016 08:28:37 GMTheader: Content-Type: text/html; charset=utf-8header: Content-Length: 14096header: Connection: closeheader: Vary: Accept-Encodingheader: Cache-Control: private, max-age=10header: Expires: Sun, 03 Jul 2016 08:28:45 GMTheader: Last-Modified: Sun, 03 Jul 2016 08:28:35 GMTheader: X-UA-Compatible: IE=10”温故而知新“
3.4 urllib2.install_opener
作用:保存创建的opener
import urllibimport urllib2def demo(): url = 'http://www.cnblogs.com/hester' headers = {'User-Agent':'Mozilla/5.0','x-my-hester':'my value'} req = urllib2.Request(url,headers=headers) s = urllib2.urlopen(req) print s.read(100) print req.headers s.close()# def request_post_debug():# data = {'username':'hester_ge','password':'xxxxxxx'}# headers = {'User-Agent':'Mozilla/5.0','x-my-hester':'my value'}# req = urllib2.Request('http://www.cnblogs.com/hester',data = urllib.urlencode(data),headers=headers)# opener = urllib2.build_opener(urllib2.HTTPHandler(debuglevel=1))# s = opener.open(req)# print s.read(100)# s.close()def install_opener(): opener = urllib2.build_opener(urllib2.HTTPHandler(debuglevel=1), urllib2.HTTPSHandler(debuglevel=1)) urllib2.install_opener(opener)if __name__ == '__main__': # request_post_debug() demo()
运行结果:
”温故而知新“ {'X-my-hester': 'my value', 'User-agent': 'Mozilla/5.0'}
如上代码更改为:
if __name__ == '__main__': # request_post_debug() install_opener() demo()
运行结果:
send: 'GET /hester HTTP/1.1\r\nAccept-Encoding: identity\r\nHost: www.cnblogs.com\r\nConnection: close\r\nX-My-Hester: my value\r\nUser-Agent: Mozilla/5.0\r\n\r\n'reply: 'HTTP/1.1 200 OK\r\n'header: Date: Sun, 03 Jul 2016 08:39:31 GMTheader: Content-Type: text/html; charset=utf-8header: Content-Length: 14096header: Connection: closeheader: Vary: Accept-Encodingheader: Cache-Control: private, max-age=10header: Expires: Sun, 03 Jul 2016 08:39:41 GMTheader: Last-Modified: Sun, 03 Jul 2016 08:39:31 GMTheader: X-UA-Compatible: IE=10”温故而知新“ {'X-my-hester': 'my value', 'User-agent': 'Mozilla/5.0'}
4、cookies模块
因HTTP协议是无状态的,服务器无法识别请求是否为同一计算机,所以需要使用cookies进行标示。
客户见浏览器先发送request给服务器,服务器收到请求后进行解析,然后发送response给客户机,set_cookies就存在与response中,由浏览器进行设置。
我们这边用到两个模块
cookielib.CookieJar 提供解析并保存cookie的接口
HTTPCookieProcessor 提供自动出来cookie的功能
#encoding=utf8import urllib2import cookielibdef handler_cookie(): cookiejar = cookielib.CookieJar() handler = urllib2.HTTPCookieProcessor(cookiejar=cookiejar) opener = urllib2.build_opener(handler,urllib2.HTTPHandler(debuglevel=1)) s = opener.open('http://www.douban.com/') print s.read(100) s.close() print '=' * 20 print cookiejar._cookies print '=' * 20 #发送第二次请求时,自动带上cookie s2 = opener.open('http://www.douban.com/') print s2.read(100) s2.close()if __name__ == '__main__': handler_cookie()
运行结果:
/usr/bin/python2.7 /home/hester/PycharmProjects/untitled/demo4.pysend: 'GET / HTTP/1.1\r\nAccept-Encoding: identity\r\nHost: www.douban.com\r\nConnection: close\r\nUser-Agent: Python-urllib/2.7\r\n\r\n'reply: 'HTTP/1.1 301 Moved Permanently\r\n'header: Date: Sun, 03 Jul 2016 10:01:41 GMTheader: Content-Type: text/htmlheader: Content-Length: 178header: Connection: closeheader: Location: https://www.douban.com/header: Server: dae