gistfile1.txt

Python 3.6.4 (default, Mar 14 2018, 11:02:01)
Type 'copyright', 'credits' or 'license' for more information
IPython 6.2.1 -- An enhanced Interactive Python. Type '?' for help.

In [1]: from functools import lru_cache

In [2]: class Adder:
   ...:     def __init__(self, n):
   ...:         self.n = n
   ...:     @lru_cache()
   ...:     def add(self, x):
   ...:         print('executing...')
   ...:         return x + self.n
   ...:

In [3]: add1 = Adder(1)

In [4]: add2 = Adder(2)

In [5]: add1.add(1)
executing...
Out[5]: 2

In [6]: add1.add(1)
Out[6]: 2

In [7]: add2.add(1)
executing...
Out[7]: 3

In [8]: add2.add(1)
Out[8]: 3