列表赋值的问题求助

jerryxjr1220

遇到个列表赋值的问题，利用for循环对lst列表赋值，但是为啥每行的赋值结果同是相同的？都是当i=19时的赋值。

1. olst = [
   
2. '08','02','22','97','38','15','00','40','00','75','04','05','07','78','52','12','50','77','91','08',
   
3. '49','49','99','40','17','81','18','57','60','87','17','40','98','43','69','48','04','56','62','00',
   
4. '81','49','31','73','55','79','14','29','93','71','40','67','53','88','30','03','49','13','36','65',
   
5. '52','70','95','23','04','60','11','42','69','24','68','56','01','32','56','71','37','02','36','91',
   
6. '22','31','16','71','51','67','63','89','41','92','36','54','22','40','40','28','66','33','13','80',
   
7. '24','47','32','60','99','03','45','02','44','75','33','53','78','36','84','20','35','17','12','50',
   
8. '32','98','81','28','64','23','67','10','26','38','40','67','59','54','70','66','18','38','64','70',
   
9. '67','26','20','68','02','62','12','20','95','63','94','39','63','08','40','91','66','49','94','21',
   
10. '24','55','58','05','66','73','99','26','97','17','78','78','96','83','14','88','34','89','63','72',
    
11. '21','36','23','09','75','00','76','44','20','45','35','14','00','61','33','97','34','31','33','95',
    
12. '78','17','53','28','22','75','31','67','15','94','03','80','04','62','16','14','09','53','56','92',
    
13. '16','39','05','42','96','35','31','47','55','58','88','24','00','17','54','24','36','29','85','57',
    
14. '86','56','00','48','35','71','89','07','05','44','44','37','44','60','21','58','51','54','17','58',
    
15. '19','80','81','68','05','94','47','69','28','73','92','13','86','52','17','77','04','89','55','40',
    
16. '04','52','08','83','97','35','99','16','07','97','57','32','16','26','26','79','33','27','98','66',
    
17. '88','36','68','87','57','62','20','72','03','46','33','67','46','55','12','32','63','93','53','69',
    
18. '04','42','16','73','38','25','39','11','24','94','72','18','08','46','29','32','40','62','76','36',
    
19. '20','69','36','41','72','30','23','88','34','62','99','69','82','67','59','85','74','04','36','16',
    
20. '20','73','35','29','78','31','90','01','74','31','49','71','48','86','81','16','23','57','05','54',
    
21. '01','70','54','71','83','51','54','69','16','92','33','48','61','43','52','01','89','19','67','48']
    
22. lst = [[None]*20]*20
    
23. for i in range(20):
    
24.     for j in range(20):
    
25.         lst[i][j]=int(olst[i*20+j])
    
26. print lst

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输出结果：

1. [[1, 70, 54, 71, 83, 51, 54, 69, 16, 92, 33, 48, 61, 43, 52, 1, 89, 19, 67, 48], [1, 70, 54, 71, 83, 51, 54, 69, 16, 92, 33, 48, 61, 43, 52, 1, 89, 19, 67, 48], [1, 70, 54, 71, 83, 51, 54, 69, 16, 92, 33, 48, 61, 43, 52, 1, 89, 19, 67, 48], [1, 70, 54, 71, 83, 51, 54, 69, 16, 92, 33, 48, 61, 43, 52, 1, 89, 19, 67, 48], [1, 70, 54, 71, 83, 51, 54, 69, 16, 92, 33, 48, 61, 43, 52, 1, 89, 19, 67, 48], [1, 70, 54, 71, 83, 51, 54, 69, 16, 92, 33, 48, 61, 43, 52, 1, 89, 19, 67, 48], [1, 70, 54, 71, 83, 51, 54, 69, 16, 92, 33, 48, 61, 43, 52, 1, 89, 19, 67, 48], [1, 70, 54, 71, 83, 51, 54, 69, 16, 92, 33, 48, 61, 43, 52, 1, 89, 19, 67, 48], [1, 70, 54, 71, 83, 51, 54, 69, 16, 92, 33, 48, 61, 43, 52, 1, 89, 19, 67, 48], [1, 70, 54, 71, 83, 51, 54, 69, 16, 92, 33, 48, 61, 43, 52, 1, 89, 19, 67, 48], [1, 70, 54, 71, 83, 51, 54, 69, 16, 92, 33, 48, 61, 43, 52, 1, 89, 19, 67, 48], [1, 70, 54, 71, 83, 51, 54, 69, 16, 92, 33, 48, 61, 43, 52, 1, 89, 19, 67, 48], [1, 70, 54, 71, 83, 51, 54, 69, 16, 92, 33, 48, 61, 43, 52, 1, 89, 19, 67, 48], [1, 70, 54, 71, 83, 51, 54, 69, 16, 92, 33, 48, 61, 43, 52, 1, 89, 19, 67, 48], [1, 70, 54, 71, 83, 51, 54, 69, 16, 92, 33, 48, 61, 43, 52, 1, 89, 19, 67, 48], [1, 70, 54, 71, 83, 51, 54, 69, 16, 92, 33, 48, 61, 43, 52, 1, 89, 19, 67, 48], [1, 70, 54, 71, 83, 51, 54, 69, 16, 92, 33, 48, 61, 43, 52, 1, 89, 19, 67, 48], [1, 70, 54, 71, 83, 51, 54, 69, 16, 92, 33, 48, 61, 43, 52, 1, 89, 19, 67, 48], [1, 70, 54, 71, 83, 51, 54, 69, 16, 92, 33, 48, 61, 43, 52, 1, 89, 19, 67, 48], [1, 70, 54, 71, 83, 51, 54, 69, 16, 92, 33, 48, 61, 43, 52, 1, 89, 19, 67, 48]]
   

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@冬雪雪冬 @SixPy

jerryxjr1220

我知道问题了，原来是列表的指针问题。用[]*n的方法得到的指针都是相同的，也就是这20行多对应着同一行，改变一行就同时改变了这20行。
后段部分代码改为：

1. lst = [[None for i in range(20)] for j in range(20)]
   
2. for i in range(20):
   
3.     for j in range(20):
   
4.         lst[i][j]=int(olst[i*20+j])
   
5. print lst

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输出结果就正常了：

1. [[8, 2, 22, 97, 38, 15, 0, 40, 0, 75, 4, 5, 7, 78, 52, 12, 50, 77, 91, 8], [49, 49, 99, 40, 17, 81, 18, 57, 60, 87, 17, 40, 98, 43, 69, 48, 4, 56, 62, 0], [81, 49, 31, 73, 55, 79, 14, 29, 93, 71, 40, 67, 53, 88, 30, 3, 49, 13, 36, 65], [52, 70, 95, 23, 4, 60, 11, 42, 69, 24, 68, 56, 1, 32, 56, 71, 37, 2, 36, 91], [22, 31, 16, 71, 51, 67, 63, 89, 41, 92, 36, 54, 22, 40, 40, 28, 66, 33, 13, 80], [24, 47, 32, 60, 99, 3, 45, 2, 44, 75, 33, 53, 78, 36, 84, 20, 35, 17, 12, 50], [32, 98, 81, 28, 64, 23, 67, 10, 26, 38, 40, 67, 59, 54, 70, 66, 18, 38, 64, 70], [67, 26, 20, 68, 2, 62, 12, 20, 95, 63, 94, 39, 63, 8, 40, 91, 66, 49, 94, 21], [24, 55, 58, 5, 66, 73, 99, 26, 97, 17, 78, 78, 96, 83, 14, 88, 34, 89, 63, 72], [21, 36, 23, 9, 75, 0, 76, 44, 20, 45, 35, 14, 0, 61, 33, 97, 34, 31, 33, 95], [78, 17, 53, 28, 22, 75, 31, 67, 15, 94, 3, 80, 4, 62, 16, 14, 9, 53, 56, 92], [16, 39, 5, 42, 96, 35, 31, 47, 55, 58, 88, 24, 0, 17, 54, 24, 36, 29, 85, 57], [86, 56, 0, 48, 35, 71, 89, 7, 5, 44, 44, 37, 44, 60, 21, 58, 51, 54, 17, 58], [19, 80, 81, 68, 5, 94, 47, 69, 28, 73, 92, 13, 86, 52, 17, 77, 4, 89, 55, 40], [4, 52, 8, 83, 97, 35, 99, 16, 7, 97, 57, 32, 16, 26, 26, 79, 33, 27, 98, 66], [88, 36, 68, 87, 57, 62, 20, 72, 3, 46, 33, 67, 46, 55, 12, 32, 63, 93, 53, 69], [4, 42, 16, 73, 38, 25, 39, 11, 24, 94, 72, 18, 8, 46, 29, 32, 40, 62, 76, 36], [20, 69, 36, 41, 72, 30, 23, 88, 34, 62, 99, 69, 82, 67, 59, 85, 74, 4, 36, 16], [20, 73, 35, 29, 78, 31, 90, 1, 74, 31, 49, 71, 48, 86, 81, 16, 23, 57, 5, 54], [1, 70, 54, 71, 83, 51, 54, 69, 16, 92, 33, 48, 61, 43, 52, 1, 89, 19, 67, 48]]

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