def _psplit(self):
nsplit_list = self._nsplit()<EOL>psplit_list = [ ]<EOL>for si in nsplit_list:<EOL><INDENT>psplit_list.extend(si._ssplit())<EOL><DEDENT>return psplit_list<EOL>
Split `self` at both north and south poles.

:return: A list of split StridedIntervals