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

Terry Reedy tjreedy at udel.edu
Thu Apr 26 15:05:23 EDT 2018


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



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