def generate(n):
lib = Library()
for i in range(0, n):
lib.append(Book(
"Author{0}".format(random.randint(1, n)),
"Title{0}".format(random.randint(1, n)),
random.randint(1950, 2015),
"Publ{0}".format(random.randint(1, n))))
return lib
