[Python-Dev] chained assignment weirdity

[Terry Reedy]

On 11/7/2012 4:39 PM, Ned Batchelder wrote:

> Just to be clear: the reference guide says that the behavior *SHOULD BE*
> (but is not yet) this:
>
>     Python 3.3.0
>      >>> {print("a"):print("b")}
>     a
>     b
>     {None: None}
>      >>> d = {}
>      >>> d[print("a")] = print("b")
>     b
>     a
>      >>>
>
> Is this or is this not "weird" to you?

Not weird. Expressions and assignment targets are each consistently 
evaluated left to right (except as *necessarily* alter by precedence), 
with expressions evaluated before targets.

What is weird -- to me ;-) -- is using side-effects in either example above.

-- 
Terry Jan Reedy