Wrote a memoize function: I do not mind feedback

Cecil Westerhof Cecil at decebal.nl
Wed Apr 29 08:06:37 CEST 2015


Op Monday 27 Apr 2015 22:35 CEST schreef Albert-Jan Roskam:

> ----- Original Message -----
>> From: Peter Otten <__peter__ at web.de>
>> To: python-list at python.org
>> Cc: 
>> Sent: Monday, April 27, 2015 4:28 PM
>> Subject: Re: Wrote a memoize function: I do not mind feedback
>>
>> Cecil Westerhof wrote:
>>
>>> I started again with Python. In Clojure you have memoize. I
>>> thought it nice to have this in Python also. So I wrote it. With a
>>> Fibonacci function to show the usefulness. You can find it here:
>>> https://github.com/CecilWesterhof/PythonLibrary
>>>
>>> I love to hear what you think of it.
>>>
>>> And ideas for other functionalities are welcome also. Übung macht
>>> den Meister.
>>
>> See also: 
>>
>> https://docs.python.org/dev/library/functools.html#functools.lru_cache
>>
>> A bit hard to find unless you already know it's there.
>
> If you Google for memoization decorator, you will easily find many
> more implementations. Not 100 percent sure, but I think the LRU
> cache decorator was not exactly light weight. I also like this one
> from Martelli's Python Cookbook, where he uses a mutable default
> argument {a dictionary} to implement memoization. I believe I went
> like this:
>
>
> def some_func(arg, _memoize={}):
> try:
> return _memoize[arg]
> except KeyError:
> result = some_expensive_operation(arg)
> _memoize[arg] = result
> return result

That is in a way the same as what I do, except I do not use an
exception. Iunderstand it is not as expensive as it was anymore, but I
do not like to use an exception (when not necessary).

-- 
Cecil Westerhof
Senior Software Engineer
LinkedIn: http://www.linkedin.com/in/cecilwesterhof



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