New submission from Darrell Long <darr...@cs.ucsc.edu>: N = 5 board_1 = [[0 for _ in range(N)] for __ in range(N)]
is not the same as: board_2= [[0]*N]*N One makes a proper list of lists (the first), the second makes a new kind of animal were board_2[1][1] = 99 changes a whole column. Oddly, testing board_1 == board_2 is True! I'm teaching Python to non-majors, and this is a tough one to explain. ---------- components: Interpreter Core files: Screen Shot 2012-05-03 at 9.05.59 PM.png messages: 159899 nosy: darrell priority: normal severity: normal status: open title: Lists: [[0]*N]*N != [[0 for _ in range(N)] for __ in range(N)] versions: Python 2.7 Added file: http://bugs.python.org/file25450/Screen Shot 2012-05-03 at 9.05.59 PM.png _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue14719> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
