I see nothing special in `[[x for x in range(1, i)] for i in range(2, 5)]`. This should be equivalent to:

__result = []; __i = None
try:
    for __i in range(2, 5):
        __result2 = []; __x = None
        try:
            for __x in range(1, __i)
                __result2.append(__x)
            __result.append(__result2)
        finally:
            del __result2, __x
finally:
    del __i