On Tue, Jun 15, 2021 at 5:12 AM Jach Feng <jf...@ms4.hinet.net> wrote: > > >>> n = [(1,2) for i in range(3)] > >>> n > [(1, 2), (1, 2), (1, 2)] > >>> id(n[0]) == id(n[1]) == id(n[2]) > True
This is three tuples. Tuples are immutable and you get three references to the same thing. > >>> m = [[1,2] for i in range(3)] > >>> m > [[1, 2], [1, 2], [1, 2]] > >>> id(m[0]) == id(m[1]) == id(m[2]) > False > >>> > These are lists. Each one is distinct. You could change one of them and the other two would remain as they are. ChrisA -- https://mail.python.org/mailman/listinfo/python-list