base_lists = [[a, b] for a in range(1, 3) for b in range(1, 6)]

def genexp():
    return tuple(x for sublist in base_lists for x in sublist)

def listcomp():
    return tuple([x for sublist in base_lists for x in sublist])

def withsum():
    return tuple(sum(base_lists, []))
import itertools as it

def withit():
    return tuple(it.chain(*base_lists))
Преобразование списка списков в кортеж в Python