4.3 `range()` 函数 The `range()` Function

If you do need to iterate over a sequence of numbers, the built-in function range() comes in handy. It generates lists containing arithmetic progressions:

如果你需要一个数值序列，内置函数range()可能会很有用，它生成一个等差级数链表。

>>> range(10)
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]

The given end point is never part of the generated list; range(10) generates a list of 10 values, exactly the legal indices for items of a sequence of length 10. It is possible to let the range start at another number, or to specify a different increment (even negative; sometimes this is called the `step'):

range(10)生成了一个包含10个值的链表，它准确的用链表的索引值填充了这个长度为10的列表，所生成的链表中不包括范围中的结束值。也可以让range操作从另一个数值开始，或者可以指定一个不同的步进值（甚至是负数，有时这也被称为“步长”）：

>>> range(5, 10)
[5, 6, 7, 8, 9]
>>> range(0, 10, 3)
[0, 3, 6, 9]
>>> range(-10, -100, -30)
[-10, -40, -70]

To iterate over the indices of a sequence, combine range() and len() as follows:

需要迭代链表索引的话，如下所示结合使用range()和len()：

>>> a = ['Mary', 'had', 'a', 'little', 'lamb']
>>> for i in range(len(a)):
...     print i, a[i]
...
0 Mary
1 had
2 a
3 little
4 lamb

4.3 range() 函数 The range() Function

4.3 `range()` 函数 The `range()` Function