python lambda

lambda表达式运作起来就像一个函数

>>> a = lambda x,y:x+y
>>> a(1,2)
3

>>> b = lambda *b:b
>>> b(1,'a')
(1, 'a')

>>> map(lambda x,y:x*y,[1,2],[3,4])
[3, 8]

None是将不相关的序列归并在一起
>>> map(None,[1,2,3],[4,5,6])
[(1, 4), (2, 5), (3, 6)]