On Dec 10, 2:00 pm, "James Mills" <[EMAIL PROTECTED]> wrote: > On Wed, Dec 10, 2008 at 3:40 PM, dongzhi <[EMAIL PROTECTED]> wrote: > > If I execute part[1], I have got 'a'. If I execute part[2], I have > > got ' '. But, if I execute part[1::2], I have got ['a', '', '']. I > > don't know why. Please tell me why. > > Perhaps you meant: > > part[1:2] > > pydoc list > > This will tell you there are 3 arguments to __getslice__ > i, j, y > > Without doing any further reading I > presume from my experience that > this works much like range and xrange > and that the 3rd parameter is the step > size. > > Consider this: > > > > >>> x = [9, 1, 2, 3, 4] > >>> x > [9, 1, 2, 3, 4] > >>> x[1:2] > [1] > >>> x[1::2] > [1, 3] > >>> x[1::1] > [1, 2, 3, 4] > >>> x[1::2] > [1, 3] > >>> x[1::3] > [1, 4] > > cheers > James > > -- > -- > -- "Problems are solved by method
Dear James Mills, Thanks a lot. Now, I know the reason. Best Regards, Liu Ming -- http://mail.python.org/mailman/listinfo/python-list
