I\'ve downloaded from a supposedly serious source a sage script. It doesn\'t work on my computer, and a quick debugging showed that a problem came from the fact that at some
In [1]: index_0 = ['foo', 'bar', 'quux'] In [2]: index_1 = [None] + index_0 In [3]: index_1[1] Out[3]: 'foo' In [4]: index_1[1:] Out[4]: ['foo', 'bar', 'quux']