[EMAIL PROTECTED] wrote: > Maybe I'm missing something but the latter is not the behaviour I'm > expecting: > >>>> a = [[1,2,3,4], [5,6,7,8]] >>>> b = a[:] >>>> b > [[1, 2, 3, 4], [5, 6, 7, 8]] >>>> a == b > True >>>> a is b > False >>>> for i in range(len(b)): > ... for x in range(4): > ... b[i][x] = b[i][x] + 10 > ... >>>> b > [[11, 12, 13, 14], [15, 16, 17, 18]] >>>> a > [[11, 12, 13, 14], [15, 16, 17, 18]] >>>>
b = a[:] does clone a, but doesn't make a deepcopy of its contents, which you are manipulating! So do [GCC 4.0.2 20050808 (prerelease) (Ubuntu 4.0.1-4ubuntu8)] on linux2 Type "help", "copyright", "credits" or "license" for more information. poWelcome to rlcompleter2 0.96 for nice experiences hit <tab> multiple times >>> import copy >>> a = [[10]] >>> b = copy.deepcopy(a) >>> b[0][0] = 20 >>> a [[10]] >>> b [[20]] >>> HTH, Diez -- http://mail.python.org/mailman/listinfo/python-list
