python基础

#获取[[[]]]
li=[1,[2,3,[4,5]]]
print(li[0])
print(li[1])
print(li[1][2])
print(li[1][2][0])
print(li[1][2][1])回车
1
[2, 3, [4, 5]]
[4, 5]
4
5

#获取[[]，[]，[]]的值
li=[[1,2,3,10],[4,5],[7,8]]
print(li[0])
print(li[0][0])
print(li[1][1])
print(li[2][0])
print(li[0][3])
[1, 2, 3, 10]
1
5
7
10

#把[[]，[]，[]]里面的hello改成5
li=[[1,2,3,10],[4,“hello”],[7,8]]
li[1][1]=5
print(li)回车
[[1, 2, 3, 10], [4, 5], [7, 8]]

#把列表[[]，[]，[]]里面的hello全部换成5
li=[[“hello”,1],[3,“hello”,“hello”]]
lis=[]
for i in range(len(li)):
print(li[i])
for j in range(len(li[i])):
print(j)
if li[i][j]==“hello”:
li[i][j]=5
print(li)回车