python2.7:urllib 和urllib2之间的区别

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?
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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。
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urllib

provides the

urlencode

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。

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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.

来源：http://www.hacksparrow.com/python-difference-between-urllib-and-urllib2.html http://www.hacksparrow.com/python-difference-between-urllib-and-urllib2.html