Python库urllib与urllib2主要区别分析

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《python: difference between urllib and urllib2》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 request 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 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，比其他几个模块好用。

相关资料

这里还有个类似的：urllib urllib2 what is the difference ?

*上也有：should i use urllib or urllib2?

python docs