Issue 9932: List of sets initialization behavior problems (original) (raw)

I'm not sure if this is the intended behavior, but it seems unusual to me. a = [set([]) for i in range(2)] evaluates to a list [set([]),set([])] and b= 2*[set([])] evaluates to [set([]),set([])]. Nothing wrong here. Nevertheless, if I do a[0].add(1), a has the value [set([1]), set([])] but b[0].add(1) evaluates to [set([1]), set([1])]. I understand that in list b, all of the sets refer to the same object in memory, nevertheless, I do not feel like this is the correct behavior.