a few pep8 whitespace cleanups

theano/gof/opt.py

@@ -651,6 +651,7 @@ class PatternSub(LocalOptimizer):
     def skip_identities(self, expr):
         if self.skip_identities_fn:
             return self.skip_identities_fn(expr)
+
     def op_key(self):
         return self.op
 

theano/tensor/elemwise.py

@@ -137,6 +137,7 @@ class DimShuffle(Op):
         d = dict(self.__dict__)
         del d['_hashval']
         return d
+
     def __setstate__(self, d):
         self.__dict__.update(d)
         self._rehash()
@@ -218,13 +219,11 @@ class DimShuffle(Op):
             rval.insert(augm, 1)
         return [rval]
 
-
     def R_op(self, inputs, eval_points):
         if None in eval_points:
             return [None]
         return self.make_node(*eval_points).outputs
 
-
     def c_code(self, node, name, inp, out, sub):
         input, = inp
         res, = out