[Python-Dev] (name := expression) doesn't fit the narrative of PEP 20

[Terry Reedy]

On 4/26/2018 6:34 AM, Greg Ewing wrote:
> Antoine Pitrou wrote:
>> Well, how do languages where assignment is an expression returning the
>> assigned value make their REPLs work?  I'm sure they don't inflict that
>> on their users, so it's certainly a solvable problem.
> 
> I can't think of any such language that has a REPL
> offhand, but here's a possible solution:
> 
> 
>     x := expr # doesn't print anything

Ugh! The only reason I would bother typing the : in a top level 
assignment would be to get the print without having to retype the name, 
as in

 >>> x = expr
 >>> x

I consider echoing top-level interactive assignments to be a feature of 
the proposal.

-- 
Terry Jan Reedy