数据结构如下,我想把数据缺失的地方(空白的地方)换成m,请问用循环怎么做呢?谢谢!
pos | name | FF047H16622 | FF047H16606 | FF047H16609 | FF047H16642 | FF047H16647 | FF047H16648 |
1 | PZE104000354 | b | b | a | a | b | b |
1 | PZE104000488 | | | | | | |
1 | PZE104000566 | | | | | | |
1 | PZE104000040 | b | b | a | a | b | b |
2 | PZE104001186 | b | b | a | a | b | b |
2 | SYNGENTA2114 | b | b | a | a | b | b |
3 | PZE104005454 | | | | | | |