Re:Python Multiple Assignment Is a Puzzle
by zwegner on Sunday July 27, 2014 @02:11PM
(#8093449)
The first--the latter isn't in order (expr3 is "evaluated" before expr2, which in this case means assignment).
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That's precisely the place where I think the description can be improved. With complex assignments, there are two parts: compute the place to store a value, and store the value there. In my mental model, the latter is better called assignment than evaluation.
With Python's evaluation/assignment order, both parts of a complex assignment happen at once--which is the source of the weird behavior in the article (A[0] is assigned to before the subscript of A[A[0] - 1] is evaluated).