2018-02-25Python2 urllib2 与 Pyth

| python2                                 | python3                                  |
| --------------------------------------- | ---------------------------------------- |
| urllib2.urlopen()                       | urllib.request.urlopen()                 |
| urllib2.install_opener()                | urllib.request.install_opener()          |
| urllib2.build_opener()                  | urllib.request.build_opener()            |
| urllib2.URLError                        | urllib.error.URLError                    |
| urllib2.HTTPError                       | urllib.error.HTTPError                   |
| urllib2.Request                         | urllib.request.Request                   |
| urllib2.OpenerDirector                  | urllib.request.OpenerDirector            |
| urllib2.BaseHandler                     | urllib.request.BaseHandler               |
| urllib2.HTTPDefaultErrorHandler         | urllib.request.HTTPDefaultErrorHandler   |
| urllib2.HTTPRedirectHandler             | urllib.request.HTTPRedirectHandler       |
| urllib2.HTTPCookieProcessor             | urllib.request.HTTPCookieProcessor       |
| urllib2.ProxyHandler                    | urllib.request.ProxyHandler              |
| urllib2.HTTPPasswordMgr                 | urllib.request.HTTPPasswordMgr           |
| urllib2.HTTPPasswordMgrWithDefaultRealm | urllib.request.HTTPPasswordMgrWithDefaultRealm |
| urllib2.AbstractBasicAuthHandler        | urllib.request.AbstractBasicAuthHandler  |
| urllib2.HTTPBasicAuthHandler            | urllib.request.HTTPBasicAuthHandler      |
| urllib2.ProxyBasicAuthHandler           | urllib.request.ProxyBasicAuthHandler     |
| urllib2.AbstractDigestAuthHandler       | urllib.request.AbstractDigestAuthHandler |
| urllib2.HTTPDigestAuthHandler           | urllib.request.HTTPDigestAuthHandler     |
| urllib2.ProxyDigestAuthHandler          | urllib.request.ProxyDigestAuthHandler    |
| urllib2.HTTPHandler                     | urllib.request.HTTPHandler               |
| urllib2.HTTPSHandler                    | urllib.request.HTTPSHandler              |
| urllib2.FileHandler                     | urllib.request.FileHandler               |
| urllib2.FTPHandler                      | urllib.request.FTPHandler                |
| urllib2.CacheFTPHandler                 | urllib.request.CacheFTPHandler           |
| urllib2.UnknownHandler                  | urllib.request.UnknownHandler            |