New in version 2.0.
Get sequence element at nonnegative cyclic index:
abjad> from abjad.tools import sequencetools
abjad> for index in range(10):
... print '%s\t%s' % (index, sequencetools.get_sequence_element_at_cyclic_index('string', index))
...
0 s
1 t
2 r
3 i
4 n
5 g
6 s
7 t
8 r
9 i
Get sequence element at negative cyclic index:
abjad> for index in range(1, 11):
... print '%s\t%s' % (-index, sequencetools.get_sequence_element_at_cyclic_index('string', -index))
...
-1 g
-2 n
-3 i
-4 r
-5 t
-6 s
-7 g
-8 n
-9 i
-10 r
Return reference to sequence element.