On Thu, May 24, 2018, 14:48 Alexander Belopolsky <alexander.belopolsky@gmail.com> wrote:

On Thu, May 24, 2018 at 4:59 PM Matt Arcidy <marcidy@gmail.com> wrote:

On Thu, May 24, 2018, 11:47 Alexander Belopolsky <alexander.belopolsky@gmail.com> wrote:
> But I do have a mathematics background, and I don't remember ever seeing
> "for x = value" used in the sense you mean.

That's so because in mathematics, "for" is spelled ":" as in

${2 a : a \in Z}$
If you can read the above, you should not have trouble reading
${2 a + b : a \in Z : b = 1}$

Inverted "A" is "for all", and colon means "such that". It may be acceptable somewhere to use a colon as you do,

See <https://en.wikipedia.org/wiki/Set_notation>. Also, "[list comprehensions] is Python's way of implementing a well-known notation for sets as used by mathematicians." <https://www.python-course.eu/list_comprehension.php>. Although, the latter uses "|" instead of ":".

My point was more along the lines of math doesn't use ":" for "for". "for" exists in math as a different symbol. Even in set builder notation ":" isn't interpretted as "for", it's "such that."

Maybe the math discussion is totally tangential. I'm not clear why I'm making these points really, apologies if I took this off course, I'm happy to concede the math and just keep my other points. I don't think "for" is bad compared to some other alternatives, but I don't see it better than ":=" in the contexts you've raised. Even in the implementation of set building, "for" is only used to build the sets element wise, not as a partitioning, and is not a property if the set itself.

Thanks,