def append2list(l1, l2=None):
	if l2 == None:
		l2 = []
	for i in l1:
		l2.append(i)
	return l2
def main():
	list1 = ["cat", "dog"]
	nlist = append2list(list1)
	print(nlist)

	list2 = ["lion"]
	nlist = append2list(["antelope"], list2)
	print(nlist)

	list3 = ["fox", "chicken"]
	nlist = append2list(list3)
	print(nlist)

if __name__ == "__main__":
	main()