原文第2章第3节
分解序列(sequence unpacking)
The pattern of binding multiple names to multiple values in a fixed-length sequence。
序列中各值赋予不同变量名。
>>> pairs = [[1, 2], [2, 2], [2, 3], [4, 4]]
>>> same_count = 0
如果执行下列代码：
>>> for x, y in pairs:
if x == y:
same_count = same_count + 1
就可以得到：
>>> same_count
2
列表推导式(list comprehension)
An expression that can performs such a sequence processing operation which can be expressed by evaluating a fixed expression for each element in a sequence and collecting the resulting values in a result sequence.
一行代码直接完成对列表的便利操作并返回值。
例如，
>>> odds = [1, 3, 5, 7, 9]
>>> [x+1 for x in odds]
[2, 4, 6, 8, 10]
# Another Example
>>> [x for x in odds if 25 % x == 0]
[1, 5]
通式：
[<map expression> for <name> in <sequence expression> if <filter expression>]
更多见这里。
列表推导式的效果也可以用高阶函数的方式来达到，但前者更为常见（个人觉得前者更利于理解）。
数据类型的闭合型
In general, a method for combining data values has a closure property if the result of combination can itself be combined using the same method.
例如，列表自身可以组成列表的元素。
其它