python 9-1 如何使用函数装饰器,定义函数装饰器，用来生成一个原函数基础添加新功能的函数，替代原函数

def memo(func):
cache = {}
def wrapper(*args):
if args not in cache:
cache[args] = func(*args)
return cache[args]
return wrapper

def memo(func):
cache = {}
def wrapper(*args):
if args not in cache:
cache[args] = func(*args)
return cache[args]
return wrapper
@memo
def fibonacci(n):
if n <= 1:
return 1
return fibonacci(n - 1) + fibonacci(n - 2)

def fibonacci2(n,cache = None):
if cache is None:
cache = {}

if n in cache:
return cache

if n <= 1:
return 1

cache
= fibonacci2(n - 1,cache) + fibonacci2(n - 2,cache)

return cache

==>一个共有10个台阶的楼梯，从下面走到上面，一次只能迈1，2，3个台阶
==>  并且不能后退，走完这个楼梯共有多少中方法

def climb(n,steps):
count = 0
if n == 0:
count = 1

elif n >0:
for step in steps:
count += climb(n-step,steps)

return count

print fibonacci2(5)

print fibonacci(50)

fibonacci = memo(fibonacci)
print fibonacci(50)

print climb(10,(1,2,3))