Hi, I saw this line of code on a recent post:
a1[:] = [x*3 for x in a1] Could somebody tells me what the [:] means? I can't find it anywhere. See context below if needed: On Dec 26, 4:46 pm, Tim Chase <python.l...@tim.thechases.com> wrote: > > What does *not* work is > > 3 * [0,1,2] > > As you know, this gives > > [0,1,2,0,1,2,0,1,2] > > What I am hoping for is > > [0,3,6] > > I see that I can use > > numpy.multiply(3,range(3)) > > but this seems overkill to me. Can you tell I am coming to Python from > > Matlab? > > The common way to do this is just > > a1 = [0,1,2] > a2 = [x * 3 for x in a1] > > or, if you need a1 to be done in place: > > a1[:] = [x*3 for x in a1] > > -tkc -- http://mail.python.org/mailman/listinfo/python-list
