class_caching.py

def fibonacci(num):
    if num <= 2:
        return 1
    return fibonacci(num - 1) + fibonacci(num - 2)

def exponential(base, exp):
    value = 1
    for i in range(exp):
        value *= base
    return value

def caching(func):
    def wrapper(self, *args):
        page = (func.__name__, ) + args
        if page in self._Principle__cache.keys():
            print('cache hit')
            return self._Principle__cache[page]
        print('cache miss')
        self._Principle__cache[page] = func(self, *args)
        return self._Principle__cache[page]
    return wrapper

class Principle(object):
    __slot__ = ['__cache']

    def __init__(self):
        self.__cache = {}

    @caching
    def fibonacci(self, num):
        return fibonacci(num)

    @caching
    def exponential(self, base, exp):
        return exponential(base, exp)

p = Principle()
print('fibonacci 35 =', p.fibonacci(35))
print('fibonacci 35 =', p.fibonacci(35))
print('2 exp 10 =', p.exponential(2, 10))
print('2 exp 10 =', p.exponential(2, 10))
print('cache = ', p._Principle__cache)

'''result
cache miss
fibonacci 35 = 9227465
cache hit
fibonacci 35 = 9227465
cache miss
2 exp 10 = 1024
cache hit
2 exp 10 = 1024
cache =  {('fibonacci', 35): 9227465, ('exponential', 2, 10): 1024}
'''