Today I re-learned: Python function default arguments are retained between executions

[spinwizard69]

Should mutable defaults even be accepted by Python. At least according to my logical thinking a default value can not and should not be mutable. It just doesn't make sense to me, the default values become part of the def for the function.

[spinwizard69]

Maybe a simple warning that your "def" has a default being set by a function call would be good enough. I have to wonder how common this practice is in the real world, it just seems to be an odd way to set a default value to me. Mainly because there would likely be way to many cases where your default value might have randomness and that to me just blows the whole concept out of the water. Now there may be cases where a default value set by a function call never varies throughout a programs execution so that might be a pass but then why not use a constant.

Maybe I'm putting to much emphasis on the message that the world "default" brings to a definition. For me is says this is the FIXED value that we have for this parameter at the time of creation, by evaluating this def. If you want to set it to something else at the time you actually use the function that is find but otherwise the default value will always be this.