urllib提供了一系列用于操作URL的功能，而urllib的request模块可以非常方便地抓取URL内容，也就是发送一个GET请求到指定的页面，然后返回HTTP的响应。
基本的网络请求示例
import urllib.request
#请求百度网页
resu = urllib.request.urlopen('https://www.baidu.com', data = None, timeout = 10)
print(resu.read(300))
#指定编码请求
with urllib.request.urlopen('https://www.baidu.com') as resu:
print(resu.read(300).decode('GBK'))
#指定编码请求
f = urllib.request.urlopen('https://www.baidu.com')
print(f.read(100).decode('utf-8'))
发送数据请求，CGI程序处理
import urllib.request
req = urllib.request.Request(url='http://localhost/cgi-bin/test.cgi', data=b'This data is passed to stdin of the CGI')
f = urllib.request.urlopen(req)
print(f.read().decode('utf-8'))
PUT请求
import urllib.request
DATA=b'some data'
req = urllib.request.Request(url='http://localhost:8080', data=DATA,method='PUT')
f = urllib.request.urlopen(req)
print(f.status)
print(f.reason)
基本的HTTP验证，登录请求
import urllib.request
# Create an OpenerDirector with support for Basic HTTP Authentication...
auth_handler = urllib.request.HTTPBasicAuthHandler()
auth_handler.add_password(realm='Application',
uri='http://xxx/test.py',
user='test',
passwd='test')
opener = urllib.request.build_opener(auth_handler)
# ...and install it globally so it can be used with urlopen.
urllib.request.install_opener(opener)
urllib.request.urlopen('http://www.example.com/login.html')
支持代理方式验证请求
proxy_handler = urllib.request.ProxyHandler({'http': 'http://www.example.com/'})
proxy_auth_handler = urllib.request.ProxyBasicAuthHandler()
proxy_auth_handler.add_password('aaa', 'bbb', 'username', 'password')
opener = urllib.request.build_opener(proxy_handler, proxy_auth_handler)
# This time, rather than install the OpenerDirector, we use it directly:
opener.open('http://www.example.com/login.html')
添加 http headers
import urllib.request
req = urllib.request.Request('http://www.example.com/')
req.add_header('Referer', 'http://www.python.org/')
r = urllib.request.urlopen(req)
添加 user-agent
import urllib.request
opener = urllib.request.build_opener()
opener.addheaders = [('User-agent', 'Mozilla/5.0')]
opener.open('http://www.example.com/')
带参数的GET 请求
import urllib.request
import urllib.parse
params = urllib.parse.urlencode({'a': 1, 'b': 2, 'c': 0})
f = urllib.request.urlopen("http://xxx/query?%s" % params)
print(f.read().decode('utf-8'))
带参数的POST请求
import urllib.request
import urllib.parse
data = urllib.parse.urlencode({'a': 1, 'b': 2, 'c': 0})
data = data.encode('utf-8')
request = urllib.request.Request("http://xxx")
# adding charset parameter to the Content-Type header.
request.add_header("Content-Type","application/x-www-form-urlencoded;charset=utf-8")
f = urllib.request.urlopen(request, data)
print(f.read().decode('utf-8'))
指定代理方式请求
import urllib.request
proxies = {'http': 'http://proxy.example.com:8080/'}
opener = urllib.request.FancyURLopener(proxies)
f = opener.open("http://www.python.org")
f.read().decode('utf-8')
无添加代理
import urllib.request
opener = urllib.request.FancyURLopener({})
f = opener.open("http://www.python.org/")
f.read().decode('utf-8')