作为一个Python菜鸟，之前一直懵懂于urllib和urllib2，以为2是1的升级版。今天看到老外写的一篇《[url=http://www.hacksparrow.com/python-difference-between-urllib-and-urllib2.html]Python: difference between urllib and urllib2[/url]》才明白其中的区别 You might be intrigued by the existence of two separate URL modules in Python -urllib and urllib2. Even more intriguing: they are not alternatives for each other. So what is the difference between urllib and urllib2, and do we need them both? 你可能对于Python中两个独立存在的-urllib2和-urllib2感到好奇。更有趣的是：它们并不是可以相互代替的。那么这两个模块间的区别是什么，并且这两个我们都需要吗？ urllib and  urllib2are both Python modules that do URL request related stuff but offer different functionalities. Their two most significant differences are listed below: urllib 和urllib2都是接受URL请求的相关模块，但是提供了不同的功能。两个最显著的不同如下： •urllib2 can accept a [url=http://docs.python.org/library/urllib2.html#urllib2.Request]Request[/url] object to set the headers for a URL request,urllib accepts only a URL. That means, you cannot masquerade your User Agent string etc. urllib2可以接受一个Request类的实例来设置URL请求的headers，urllib仅可以接受URL。这意味着，你不可以伪装你的User Agent字符串等。 •urllib provides the [url=http://docs.python.org/library/urllib.html#urllib.urlencode]urlencode[/url] method which is used for the generation of GET query strings, urllib2 doesn't have such a function. This is one of the reasons why urllib is often used along with urllib2. urllib提供urlencode方法用来GET查询字符串的产生，而urllib2没有。这是为何urllib常和urllib2一起使用的原因。   For other differences between urllib and urllib2 refer to their documentations, the links are given in the References section. Tip: if you are planning to do HTTP stuff only, check out httplib2, it is much better than httplib or urllib or urllib2. 提示：如果你仅做HTTP相关的，看一下[url=http://code.google.com/p/httplib2/]httplib2[/url]，比其他几个模块好用。 [b]相关资料 [/b] 这里还有个类似的[url=http://www.velocityreviews.com/forums/t326690-urllib-urllib2-what-is-the-difference.html]问答[/url]：urllib urllib2 what is the difference ? stackoverflow上也有：[url=http://stackoverflow.com/questions/2018026/should-i-use-urllib-or-urllib2]Should I use urllib or urllib2?[/url] Python Docs