Peter Otten at 2017/4/12 UTC+8 PM 8:13:53 wrote: > I should add that you can write > > >>>> lr = [[1], [0]] > >>>> lx = [] > >>>> for i in range(len(lr)): > > ... lx = lr[i][:] > > ... lx.append(0) > > ... lr[i].append(1) > > ... lr.append(lx) > > ... > >>>> lr > >[[1, 1], [0, 1], [1, 0], [0, 0]] > > > > idiomatially as > > >>> lr = [[1], [0]] > >>> [inner + tail for tail in [[1], [0]] for inner in lr] > [[1, 1], [0, 1], [1, 0], [0, 0]] > > Note that there is a difference -- the resulting list does not share any > lists with the original `lr` as concatenating two lists produces a new one: > > >>> a = [1] > >>> b = [2] > >>> c = a + b > >>> a is c > False > >>> b is c > False
I was a little embarrassed when looking at my codes. It may take me a long time to get used to thinking in the "Pythonic" way:-( But definitely I have learned much from this forum:-) -- https://mail.python.org/mailman/listinfo/python-list
