Python3中使用urllib的方法详解(header,代理,超时,认证,异常处理)

yipeiwu_com6年前Python基础

我们可以利用urllib来抓取远程的数据进行保存哦,以下是python3 抓取网页资源的多种方法,有需要的可以参考借鉴。

1、最简单

import urllib.request
response = urllib.request.urlopen('http://python.org/')
html = response.read()

2、使用 Request

import urllib.request
req = urllib.request.Request('http://python.org/')
response = urllib.request.urlopen(req)
the_page = response.read()

3、发送数据

#! /usr/bin/env python3
import urllib.parse
import urllib.request
url = 'http://localhost/login.php'
user_agent = 'Mozilla/4.0 (compatible; MSIE 5.5; Windows NT)'
values = {
'act' : 'login',
'login[email]' : 'yzhang@i9i8.com',
'login[password]' : '123456'
}
data = urllib.parse.urlencode(values)
req = urllib.request.Request(url, data)
req.add_header('Referer', 'http://www.python.org/')
response = urllib.request.urlopen(req)
the_page = response.read()
print(the_page.decode("utf8"))

4、发送数据和header

#! /usr/bin/env python3
import urllib.parse
import urllib.request
url = 'http://localhost/login.php'
user_agent = 'Mozilla/4.0 (compatible; MSIE 5.5; Windows NT)'
values = {
'act' : 'login',
'login[email]' : 'yzhang@i9i8.com',
'login[password]' : '123456'
}
headers = { 'User-Agent' : user_agent }
data = urllib.parse.urlencode(values)
req = urllib.request.Request(url, data, headers)
response = urllib.request.urlopen(req)
the_page = response.read()
print(the_page.decode("utf8"))

5、http 错误

#! /usr/bin/env python3
import urllib.request
req = urllib.request.Request('//www.jb51.net ')
try:
urllib.request.urlopen(req)
except urllib.error.HTTPError as e:
print(e.code)
print(e.read().decode("utf8"))

6、异常处理1

#! /usr/bin/env python3
from urllib.request import Request, urlopen
from urllib.error import URLError, HTTPError
req = Request("//www.jb51.net /")
try:
response = urlopen(req)
except HTTPError as e:
print('The server couldn't fulfill the request.')
print('Error code: ', e.code)
except URLError as e:
print('We failed to reach a server.')
print('Reason: ', e.reason)
else:
print("good!")
print(response.read().decode("utf8"))

7、异常处理2

#! /usr/bin/env python3
from urllib.request import Request, urlopen
from urllib.error import URLError
req = Request("//www.jb51.net /")
try:
response = urlopen(req)
except URLError as e:
if hasattr(e, 'reason'):
print('We failed to reach a server.')
print('Reason: ', e.reason)
elif hasattr(e, 'code'):
print('The server couldn't fulfill the request.')
print('Error code: ', e.code)
else:
print("good!")
print(response.read().decode("utf8"))

8、HTTP 认证

#! /usr/bin/env python3
import urllib.request
# create a password manager
password_mgr = urllib.request.HTTPPasswordMgrWithDefaultRealm()
# Add the username and password.
# If we knew the realm, we could use it instead of None.
top_level_url = "https://www.jb51.net /"
password_mgr.add_password(None, top_level_url, 'rekfan', 'xxxxxx')
handler = urllib.request.HTTPBasicAuthHandler(password_mgr)
# create "opener" (OpenerDirector instance)
opener = urllib.request.build_opener(handler)
# use the opener to fetch a URL
a_url = "https://www.jb51.net /"
x = opener.open(a_url)
print(x.read())
# Install the opener.
# Now all calls to urllib.request.urlopen use our opener.
urllib.request.install_opener(opener)
a = urllib.request.urlopen(a_url).read().decode('utf8')
print(a)

9、使用代理

#! /usr/bin/env python3
import urllib.request
proxy_support = urllib.request.ProxyHandler({'sock5': 'localhost:1080'})
opener = urllib.request.build_opener(proxy_support)
urllib.request.install_opener(opener)

a = urllib.request.urlopen("//www.jb51.net ").read().decode("utf8")
print(a)

10、超时

#! /usr/bin/env python3
import socket
import urllib.request
# timeout in seconds
timeout = 2
socket.setdefaulttimeout(timeout)
# this call to urllib.request.urlopen now uses the default timeout
# we have set in the socket module
req = urllib.request.Request('//www.jb51.net /')
a = urllib.request.urlopen(req).read()
print(a)

总结

以上就是这篇文章的全部内容,希望本文的内容对大家学习或使用python能有所帮助,如果有疑问大家可以留言交流。

相关文章

Python版微信红包分配算法

红包分配算法代码实现发给大家,祝红包大丰收! #coding=gbk import random import sys #print random.randint(0, 99)...

pytorch 可视化feature map的示例代码

之前做的一些项目中涉及到feature map 可视化的问题,一个层中feature map的数量往往就是当前层out_channels的值,我们可以通过以下代码可视化自己网络中某层的f...

Python3 log10()函数简单用法

描述 log10() 方法返回以10为基数的x对数,x>0。 语法 以下是 log10() 方法的语法: import math math.log10( x ) 注意...

详解Python中的条件判断语句

详解Python中的条件判断语句

 一个else语句可以使用if语句结合起来。如果在if语句中的条件表达式解析为0或false值,那么else语句包含代码执行。 else语句是可选的声明,并if语句下面最多只有...

python字符串Intern机制详解

python字符串Intern机制详解

字符串在 Python 中是最简单也是最常用的数据类型之一,在 CPython 中字符串的实现原理使用了一种叫做 Intern(字符串驻留)的技术来提高字符串效率。究竟什么是 inter...