Thank you, yes that surprised me too. I know that they’ve made some improvements so I’m expecting them to be available in a newer release, then I’ll try it again.

Sorry, not sure how that happened! Yes, here it is: https://blog.polaris64.net/post/verlet-physics-playground/

…We did not want to contact FlyCASS first as it appeared to be operated only by one person and we did not want to alarm them. On April 23rd, we were able to disclose the issue to the Department of Homeland Security, who acknowledged the issue and confirmed that they “are taking this very seriously”.

I think the owner of FlyCASS was sufficiently alarmed!

A list comprehension is used to convert and/or filter elements of another iterable, in your case a range but this could also be another list. So you can think of it as taking one list, filtering/converting each element and producing a new list as a result.

So there’s no need to append to any list as that’s implicit in the comprehension.

For example, to produce a list of all squares in a range you could do:

[x*x for x in range(10)]

This would automatically “append” each square to the resulting list, there’s no need to do that yourself.