2014年6月12日木曜日 14時43分42秒 UTC+9 Steven D'Aprano: > On Wed, 11 Jun 2014 21:56:06 -0700, hito koto wrote: > > > > > I want to use while statement, > > > > > > for example: > > >>>> def foo(x): > > > ... y = [] > > > ... while x !=[]: > > > ... y.append(x.pop()) > > > ... return y > > > ... > > >>>> print foo(a) > > > [[10], [5, 6, 7, 8, 9], [1, 2, 3, 4]] > > >>>> a > > > [] but this is empty > > >>>> so,I want to leave a number of previous (a = [[1, 2, 3, 4],[5, 6, 7, > > >>>> 8, 9],[10]]) > > > > > > I wouldn't use a while statement. The easy way is: > > > > py> a = [[1, 2, 3, 4],[5, 6, 7, 8, 9],[10]] > > py> y = a[::-1] > > py> print y > > [[10], [5, 6, 7, 8, 9], [1, 2, 3, 4]] > > py> print a > > [[1, 2, 3, 4], [5, 6, 7, 8, 9], [10]] > > > > If you MUST use a while loop, then you need something like this: > > > > > > def foo(x): > > y = [] > > index = 0 > > while index < len(x): > > y.append(x[i]) > > i += 1 > > return y > > > > > > This does not copy in reverse order. To make it copy in reverse order, > > index should start at len(x) - 1 and end at 0. > > > > > > > > -- > > Steven
Hi, Thank you! -- https://mail.python.org/mailman/listinfo/python-list
