alt Hacker News> list object is constructed once and assigned to both variables
Ummm no the list is constructed once and assigned to b and then b is assigned to a. It would be crazy semantics if `a = b = ...` meant `a` was assigned `...`.
Edit: I'm wrong it's left to right not right to left, which makes the complaint in the article even dumber.
Replies
ayhanfuat • today at 3:37 PM
> then b is assigned to a
Wouldn't that require a LOAD_FAST? Also a is assigned first (from left to right) so a = ... happens either way.
It’s assigned left to right, not right to left. It’s documented in the Python language reference.
> An assignment statement evaluates the expression list and assigns the single resulting object to each of the target lists, from left to right.
Consider this:
If assignment were to happen right to left, you would get a NameError exception because the first assignment would require an unbound variable.