# 通过len() 来确定中间位置，这种方法更加通用。
group_list = ['Tom', 'Allen', 'Jane', 'William', 'Tony' ]
length = len(group_list)
group1 =group_list[:2]
group2 = group_list[length//2-1:length//2+2]
group3 = group_list[-2:]
print(group1)
print(group2)
print(group3)