校园网站建设情况,邮件服务器是不是网站服务器,短视频拍摄,做电商网站公司test_list []
dic1 {}
test_list [dic1 for _ in range(3)]
ll [1, 2, 3]for i in range(3):test_list[i][value] ll[i]print(test_list)运行结果#xff1a;每次赋值都更改了所有项
原因#xff1a;python的二位数据创建方式就是这样#xff0c;官方文档中有描述Wha…test_list []
dic1 {}
test_list [dic1 for _ in range(3)]
ll [1, 2, 3]for i in range(3):test_list[i][value] ll[i]print(test_list)运行结果每次赋值都更改了所有项
原因python的二位数据创建方式就是这样官方文档中有描述What has happened is that [[]] is a one-element list containing an empty list, so all three elements of [[]] * 3 are references to this single empty list. Modifying any of the elements of lists modifies this single list. You can create a list of different lists this way: lists [[] for i in range(3)]lists[0].append(3)lists[1].append(5)lists[2].append(7)lists
[[3], [5], [7]]
那么将上述代码修改为
test_list []
test_list [{} for _ in range(3)]
ll [1, 2, 3]for i in range(3):test_list[i][value] ll[i]print(test_list)结果正确
