QuerySelectMultipleField reorders saved data about wtforms HOT 1 CLOSED

There's nothing special about valuelist, it's just a plain list of strings.
There's no order retained in ._formdata, as you know, sets don't retain ordering.
The ._formdata is an internal value that you're not supposed to use, that's why it's prefixed with an underscore. If you want to get the form data as it was sent in-order, you can use .raw_data on the field.
In accessing the data property it iterates the query in the order the query is returned and then builds a list which then has the same ordering consistent with the order in which the query is returned. Having _formdata be a set just increases the speed of the comparisons to be O(1) for the purpose it's used for.

P.S. Please don't re-post closed tickets. I closed your original ticket #53 because you made assumptions based on a limited understanding of the code and if you had actually tested the QuerySelectField, you'd find that the thing you were requesting to happen was already the case. If you could provide concrete proof that the data property does not provide consistent ordering with the query, that's a valid basis, but we already have tests that prove it does work.

from wtforms.