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@lru_cache on functions with no arguments

Terry Reedy tjreedy at udel.edu
Mon Jul 31 21:32:10 EDT 2017 
On 7/31/2017 7:31 PM, tom at tomforb.es wrote:
> As part of the Python 3 cleanup in Django there are a fair few uses of @functools.lru_cache on functions that take no arguments.

This makes no sense to me.  If the function is being called for 
side-effects, then it should not be cached.  If the function is being 
called for a result, different for each call, calculated from a changing 
environment, then it should not be cached.  (Input from disk is an 
example.) If the function returns a random number, or a non-constant 
value from an oracle (such as a person), it should not be cached.  If 
the function returns a constant (possible calculated once), then the 
constant should just be bound to a name (which is a form of caching) 
rather than using the overkill of an lru cache.  What possibility am I 
missing?

-- 
Terry Jan Reedy
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