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  • python urllib、urlparse、urllib2、cookielib

    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 urllib

f = 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)
<type 'tuple'>

print filename[0]
print filename[1]

    输出：

    '/tmp/tmp8eVLjq'

<httplib.HTTPMessage instance at 0xb6a363ec>

    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：

    <type 'tuple'>
'/home/dzhwen/pythonxe6x96x87xe4xbbxb6/Homework/urllib/google.html'
<httplib.HTTPMessage instance at 0xb6e2c38c>

    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 urllib

params=urllib.urlencode({'spam':1,'eggs':2,'bacon':0})
f=urllib.urlopen("http://python.org/query?%s" % params)
print f.read()

    POST方法：　　

    import urllib

parmas = 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 urllib
import urlparse

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

if __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 urllib
import urllib2

def 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：

    <!DOCTYPE html>
<html lang="zh-cn">
<head>
<meta charset="utf-8"/>
<title>”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 urllib
import urllib2

def 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：

    <!DOCTYPE html>
<html lang="zh-cn">
<head>
<meta charset="utf-8"/>
<title>”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
    1. ProxyHandler
    2. UnknownHandler
    3. HTTPHandler
    4. HTTPDefaultHandler
    5. HTTPRedirectHandler
    6. FTPHandler
    7. FileHandler
    8. HTTPErrorHandler
    9. HTTPSHandler

    返回：

    • OpenerDirector
    import urllib
import urllib2

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()

if __name__ == '__main__':
	request_post_debug()

    运行结果：

    send: 'POST /hester HTTP/1.1
Accept-Encoding: identity
Content-Length: 35
Host: www.cnblogs.com
X-My-Hester: my value
User-Agent: Mozilla/5.0
Connection: close
Content-Type: application/x-www-form-urlencoded

username=hester_ge&password=xxxxxxx'
reply: 'HTTP/1.1 200 OK
'
header: Date: Sun, 03 Jul 2016 08:28:37 GMT
header: Content-Type: text/html; charset=utf-8
header: Content-Length: 14096
header: Connection: close
header: Vary: Accept-Encoding
header: Cache-Control: private, max-age=10
header: Expires: Sun, 03 Jul 2016 08:28:45 GMT
header: Last-Modified: Sun, 03 Jul 2016 08:28:35 GMT
header: X-UA-Compatible: IE=10
<!DOCTYPE html>
<html lang="zh-cn">
<head>
<meta charset="utf-8"/>
<title>”温故而知新“

     3.4 urllib2.install_opener

    作用：保存创建的opener

    import urllib
import urllib2

def 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：

    <!DOCTYPE html>
<html lang="zh-cn">
<head>
<meta charset="utf-8"/>
<title>”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
Accept-Encoding: identity
Host: www.cnblogs.com
Connection: close
X-My-Hester: my value
User-Agent: Mozilla/5.0

'
reply: 'HTTP/1.1 200 OK
'
header: Date: Sun, 03 Jul 2016 08:39:31 GMT
header: Content-Type: text/html; charset=utf-8
header: Content-Length: 14096
header: Connection: close
header: Vary: Accept-Encoding
header: Cache-Control: private, max-age=10
header: Expires: Sun, 03 Jul 2016 08:39:41 GMT
header: Last-Modified: Sun, 03 Jul 2016 08:39:31 GMT
header: X-UA-Compatible: IE=10
<!DOCTYPE html>
<html lang="zh-cn">
<head>
<meta charset="utf-8"/>
<title>”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=utf8
import urllib2
import cookielib

def 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.py
send: 'GET / HTTP/1.1
Accept-Encoding: identity
Host: www.douban.com
Connection: close
User-Agent: Python-urllib/2.7

'
reply: 'HTTP/1.1 301 Moved Permanently
'
header: Date: Sun, 03 Jul 2016 10:01:41 GMT
header: Content-Type: text/html
header: Content-Length: 178
header: Connection: close
header: Location: https://www.douban.com/
header: Server: dae
<!DOCTYPE HTML>
<html lang="zh-cms-Hans" class="">
<head>
<meta charset="UTF-8">
<meta name="descrip
====================
{'.douban.com': {'/': {'ll': Cookie(version=0, name='ll', value='"118163"', port=None, port_specified=False, domain='.douban.com', domain_specified=True, domain_initial_dot=True, path='/', path_specified=True, secure=False, expires=1499076101, discard=False, comment=None, comment_url=None, rest={}, rfc2109=False), 'bid': Cookie(version=0, name='bid', value='dDz4rCqWvcQ', port=None, port_specified=False, domain='.douban.com', domain_specified=True, domain_initial_dot=True, path='/', path_specified=True, secure=False, expires=1499076101, discard=False, comment=None, comment_url=None, rest={}, rfc2109=False)}}}
====================
send: 'GET / HTTP/1.1
Accept-Encoding: identity
Host: www.douban.com
Cookie: ll="118163"; bid=dDz4rCqWvcQ
Connection: close
User-Agent: Python-urllib/2.7

'
reply: 'HTTP/1.1 301 Moved Permanently
'
header: Date: Sun, 03 Jul 2016 10:01:42 GMT
header: Content-Type: text/html
header: Content-Length: 178
header: Connection: close
header: Location: https://www.douban.com/
header: Server: dae
<!DOCTYPE HTML>
<html lang="zh-cms-Hans" class="">
<head>
<meta charset="UTF-8">
<meta name="descrip

Process finished with exit code 0




    　　

    　　

    　　

    　　

    　　

    　　
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  • 原文地址：https://www.cnblogs.com/hester/p/5420696.html
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