1. 将3*3的矩阵转换成一维数组;
3*3矩阵:[
[1,2,3],
[4,5,6],
[7,8,9]
]
一维数组: [1,2,3,4,5,6,7,8,9]
方法一
li = [
[1,2,3],
[4,5,6],
[7,8,9]
]
li1 = []
for item1 in li: #[1,2,3] [4,5,6] [7,8,9]
for item2 in item1:
li1.append(item2)
print(li1)
方法二
li = [
[1,2,3],
[4,5,6],
[7,8,9]
]
print([item2 for item1 in li for item2 in item1])
2将第一题中矩阵中的偶数拿出来 变成一维数组
方法一
li = [
[1,2,3],
[4,5,6],
[7,8,9]
]
resLi = []
for item1 in li: # [1,2,3] [4,5,6] [7,8,9]
for item2 in item1:
if item2 %2 ==0:
resLi.append(item2)
print(resLi)
方法二
li = [
[1,2,3],
[4,5,6],
[7,8,9]
]
print([item2 for item1 in li for item2 in item1 if item2 %2==0])