The future of "frozen" types as the number of CPU cores increases

[Terry Reedy]

On 2/16/2010 3:15 PM, John Nagle wrote:
> In the beginning, Python had some types which were "frozen",
 > and some which weren't.

In the beginning, there was only one 'frozen' general purpose collection 
type, the tuple. And Guido resisted the suggestion that lists and tuple 
were mutable and frozen versions of each other.

However, things have changed, and lists and tuple *are* effectively 
mutable and hashable versions of each other, and we have the three other 
pairs you mentioned. The idea of freeze() may have been floated (and 
punctured) during Py3 discussions, but I think it a fairly good one.

Terry Jan Reedy