andrew...@gmail.com於 2012年10月29日星期一UTC+8上午11時12分11秒寫道: > The slice operator does not give any way (I can find!) to take slices from > negative to positive indexes, although the range is not empty, nor the > expected indexes out of range that I am supplying. > > > > Many programs that I write would require introducing variables and logical > statements to correct the problem which is very lengthy and error prone > unless there is a simple work around. > > > > I *hate* replicating code every time I need to do this! > > > > I also don't understand why slice() is not equivalent to an iterator, but can > replace an integer in __getitem__() whereas xrange() can't. > > > > > > Here's an example for Linux shell, otherwise remove /bin/env... > > {{{#!/bin/env python > > a=[1,2,3,4,5,6,7,8,9,10] > > print a[-4:3] # I am interested in getting [7,8,9,10,1,2] but I get []. > > }}} I'll suggest to use the reverse method to get what you want.
Of course, the reverse method is not efficient for a list of a huge number of objects in python. -- http://mail.python.org/mailman/listinfo/python-list