python中列表的最大值、最小值、求和、平均数

>>> test1 = [3,5,1,9,2,7,4]
>>> type(test1)
<class 'list'>
>>> len(test1)
7
>>> min(test1)
1
>>> max(test1)
9
>>> sum(test1)
31
>>> sum(test1) / len(test1)
4.428571428571429