"Terry Reedy" firstname.lastname@example.org wrote in message news:email@example.com...
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