python 内置&&递归

lambda

优点：

1：可以简单使用一个脚本来替代我们的函数

2：不用考虑命名的问题

3：简化代码的可读性，不用跳转到def了，省去这样的步骤

内置函数：bif

filter：过滤器

map：映射

 >>> lambda x: 2*x+1
 <function <lambda> at 0x00000000026C6AC8>
 >>> g=lambda x: 2*x+1
 >>> g(3)
 7
 >>> help(filter)
 Help on built-in function filter in module __builtin__:
 
 filter(...)
     filter(function or None, sequence) -> list, tuple, or string
 
     Return those items of sequence for which function(item) is true.  If
     function is None, return the items that are true.  If sequence is a tuple
     or string, return the same type, else return a list.
 
 >>> filter(None,[1,0,True,False])
 [1, True]
 >>>
 >>>
 >>> tmp=range(10)
 >>> tmp
 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
 >>> def fun(x):
     return x%2
 
 >>> filter(fun,tmp)
 [1, 3, 5, 7, 9]
 >>> list(filter(lambda x:x%2,range(10)))
 [1, 3, 5, 7, 9]
 >>> list(map(lambda x:x*2,range(10)))
 [0, 2, 4, 6, 8, 10, 12, 14, 16, 18]
 >>> 

递归

python限制的递归深度大概几百层，但是可以手动设置

》》》import sys

>>> sys.setrecursionlimit(10000)

python---------------------------------------eg'1------------------