Попробуйте,
A = ['loans', 'mercedez', 'bugatti', 'a4', 'trump', 'usa', 'election', 'president', 'galaxy', '7s', 'canon', 'macbook', 'beiber', 'spiderman', 'marvels', 'ironmen']
B = ['loans', 'network', 'washington', 'trump', 'canon', 'london']
print('\n'.join([i for i in B if i not in A]))
вывод:
network
washington
london