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# Memoization in Python

 P: n/a Following Antti Karttunen suggestion, I wrote the following simple decorator for creating functions with cache (something like 'option remember' in Maple). Just wanted to share it: def function_with_cache(f): def new_f(*args): if args in new_f.cache: return new_f.cache[args] result=f(*args) new_f.cache[args]=result return result new_f.cache={} new_f.func_name=f.func_name return new_f For example, @function_with_cache def A000045(n): if n<2: return n return A000045(n-1)+A000045(n-2) A000045(3) 2 A000045.cache {(2,): 1, (0,): 0, (3,): 2, (1,): 1} Or, another example, @function_with_cache def binomial(m,n): if m <0 or n >m: return 0 if n==0 or m==n: return 1 return binomial(m-1,n)+binomial(m-1,n-1) binomial(5,3) 10 binomial.cache {(3, 2): 3, (3, 3): 1, (3, 1): 3, (2, 1): 2, (2, 0): 1, (4, 3): 4, (2, 2): 1, (4, 2): 6, (1, 0): 1, (1, 1): 1, (5, 3): 10} Alec Mihailovs http://mihailovs.com/Alec/ Jan 5 '07 #1