Gabriel wrote: > Hi all > > Just wondering if someone could clarify this behaviour for me, please? > >>>> tasks = [[]]*6 >>>> tasks > [[], [], [], [], [], []] >>>> tasks[0].append(1) >>>> tasks > [[1], [1], [1], [1], [1], [1]] > > Well what I was expecting to end up with was something like: > >>> tasks > [[1], [], [], [], [], []] > > > I got this example from page 38 of Beginning Python.
The "problem" is that all the lists inside the outer list are the same list - you can check that with id(tasks[0]) == id(tasks[1]) So instead of creating a list of list by the *-operator that only multiplies the references (which is fine immutable objects like strings or numbers), you need to explicitly create new lists, e.g. with a list-comprehension: tasks = [[] for _ in xrange(6)] Try this and everything will work as expected. Diez -- http://mail.python.org/mailman/listinfo/python-list
