python 使用 urllib2

 使用basic auth 的３种方式

1. 设置header

import urllib2
from base64 import encodestring

headers = {'Content-Type': 'application/json;charset=UTF-8',
               'Authorization': 'Basic %s'% encodestring('%s:%s'%(user, password))[:-1]}


def http_request(url, data_json, headers):
    # data_json is json string, if it is not null then this is a POST request else this is a GET request
    req = urllib2.Request(url, data_json, headers=headers)
    response = urllib2.urlopen(req)
    return response.getcode(), response.read()

2. 使用 HTTPBasicAuthHandler, 并install。执行认证一次，可以多次访问

import urllib2
# Create an OpenerDirector with support for Basic HTTP Authentication...
auth_handler = urllib2.HTTPBasicAuthHandler()
auth_handler.add_password(realm='PDQ Application',
                          uri='https://mahler:8092/site-updates.py',
                          user='klem',
                          passwd='kadidd!ehopper')
opener = urllib2.build_opener(auth_handler)
# ...and install it globally so it can be used with urlopen.
urllib2.install_opener(opener)

# 可以以配置的用户，依次访问多个url
urllib2.urlopen('http://www.example.com/login.html')
urllib2.urlopen('http://www.example.com/login.html')

3. 

含有身份验证的网页，无论是 http 还是 https， 以下代码均适用。(如果还是报权限问题，有可能是 header 问题。)

import urllib2

class WebRequester(object):
    def __init__(self, top_level_url, user, passwd):
        password_mgr = urllib2.HTTPPasswordMgrWithDefaultRealm()
        password_mgr.add_password(None, top_level_url, user, passwd)
        handler = urllib2.HTTPBasicAuthHandler(password_mgr)
        opener = urllib2.build_opener(handler)
        urllib2.install_opener(opener)

    def get_page(self, url):
        fd = urllib2.urlopen(url)
        return fd.read().encode('utf-8')

说明：在init中，install 了一个openner, 作为default 的openner, 之后的请求默认由它发出（如果不另外声明），urlopen 会使用该openner。

但是 open 不会使用它。所以，临时请求网页，可以直接使用 urllib2.build_opener().open(url)。

opener = urllib2.build_opener()
fd = opener.open(url)