[Python-Dev] Re: Re: Caching objects in memory

[Terry Reedy]

"Terry Reedy" <tjreedy at udel.edu> wrote in message 
news:d4jm79$uji$1 at sea.gmane.org...
> Guido:
>
> But for *immutable* objects (like numbers, strings and tuples) the
> implementation is free to use caching. In practice, I believe ints
> between -5 and 100 are cached, and 1-character strings are often
> cached (but not always).
>
> Hope this helps! I would think this is in the docs somewhere but
> probably not in a place where one would ever think to look...
>
> -----------

To be clearer, the above quotes what Guido wrote in the post of his that I 
am responding to.  Only the below is my response.

> I am sure that the fact that immutables *may* be cached is in the ref 
> manual, but I have been under the impression that the private, *mutable* 
> specifics for CPython are intentionally omitted so that people will not 
> think of them as either fixed or as part of the language/library.
>
> I have previously suggested that there be a separate doc for CPython 
> implementation details like this that some people want but which are not 
> part of the language or library definition.
>
Terry J. Reedy