Specific iterator in one line

[Bearophile]

Filip Gruszczyński:
> [1, 0, 0, 1] -> ['b', 'b', 'a', 'a', 'b', 'b']

I like this version (43 golf holes), it's readable enough:

[c for d in[1,0,0,1]for c in("a","bb")[d]]

Bye,
bearophile