On Mar 23, 11:34 am, [EMAIL PROTECTED] wrote: > Hi there. > I felt like I already know my toys around but it looks that I'm still > newbie on some points. > > So here goes problem: > > Lets say that we have list to copy: > > a = [1,2,3] > b = a[:] > a[0] = 5 > > a > > > [5,2,3] > b > >[1,2,3] > > So far so good > > But... let's say that "a" also contains lists: > > a = [1,2,[5,6,7]] > b = a[:] > > a[0] = 55 > a > > > [55,2,[5,6,7]] > b > > [1,2,[5,6,7]] > > Looks OK but... > > a[2][0] = 99 > a > > > [55,2,[99,6,7]] > b > > [1,2,[99,6,7]] > > So - it looks that in list "b" there copy of all objects from list "a" > including not copy of list [5,6,7] but reference to it.
Right; that's what it's called a "shallow copy". > Is there simple way to copy a into b (like a[:]) with all copies of > all objects going as deep as possible? Yes, there is: from copy import deepcopy b = deepcopy(a) HTH, George -- http://mail.python.org/mailman/listinfo/python-list
