def split(self):
        rule = self.rule
        if not self.is_leaf:
            rule = rule[:-1]
        if not rule:
            return Route('/'), None
        bits = ('/'+rule).split('/')
        last = Route(bits[-1] if self.is_leaf else bits[-1] + '/')
        if len(bits) > 1:
            return Route('/'.join(bits[:-1]) + '/'), last
        else:
            return last, None
Match a variable with either of the `exp(x)` or `-exp(x)` patterns.
dataset/ETHPy150Open quantmind/pulsar/pulsar/apps/wsgi/route.py/Route.split--crossover with--dataset/ETHPy150Open rizar/attention-lvcsr/libs/Theano/theano/tensor/nnet/sigm.py/is_exp