def _pairwise(iterable):
a, b = itertools.tee(iterable)<EOL>next(b, None)<EOL>if sys.version_info.major == <NUM_LIT:2>:<EOL><INDENT>return itertools.izip(a, b)<EOL><DEDENT>else:<EOL><INDENT>return zip(a, b)<EOL><DEDENT>
Wrapper on itertools for SVD_magnitude.