Python--xrange()和range()的区别不同

Python 2.7.3 (default, Apr 10 2012, 23:24:47) [MSC v.1500 64 bit (AMD64)] on win32
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>>> range(5)
[0, 1, 2, 3, 4]
>>> xrange(5)
xrange(5)
>>> print range.__doc__
range([start,] stop[, step]) -> list of integers

Return a list containing an arithmetic progression of integers.
range(i, j) returns [i, i+1, i+2, ..., j-1]; start (!) defaults to 0.
When step is given, it specifies the increment (or decrement).
For example, range(4) returns [0, 1, 2, 3]. The end point is omitted!
These are exactly the valid indices for a list of 4 elements.
>>> print xrange.__doc__
xrange([start,] stop[, step]) -> xrange object

Like range(), but instead of returning a list, returns an object that
generates the numbers in the range on demand. For looping, this is
slightly faster than range() and more memory efficient.
>>>
在 Python 2.x 版本中， range() 返回的结果是一个列表对象，而 xrange()返回的结果是一个 xrange对象，__doc__认真看，对于循环来说， xrange()比 range()快点，内存效率也要高点。

在 Python 3.x版本中， 挖坑TODO  ------Windows环境和 阿里云服务器暂时没有 3.0版本。

可以看一些英文：

点击打开链接  这篇文章很好，有 how to use,   The Difference Between xrange and range in Python,  Example,  In Python 3.0 Deprecation of Python’s xrange

http://www.quora.com/Python-programming-language-1/What-is-the-difference-between-range-and-xrange-how-has-this-changed-over-time

点击打开链接  http://stackoverflow.com/questions/135041/should-you-always-favor-xrange-over-range

In python 3, range() is a generator anyway and xrange does not exist.