# list_demo = [1,2,3]
# print(list('abc'))
# list_demo.append(1)
# print(list_demo)
# list_demo.sort()
# print(list_demo)
# list_demo.sort(reverse=True)
# print(list_demo)

#输出[1,9]的平方  使用推导式
list2 = []
list2= [i**2 for i in range(1,10)]
print(list2)
