Add import.

theano/tensor/__init__.py

@@ -55,3 +55,5 @@ from theano.gradient import Rop, Lop, grad, numeric_grad, verify_grad, \
     jacobian, hessian
 
 from theano.tensor.sort import sort
+from extra_ops import (DiffOp, bincount, squeeze,
+                       repeat, bartlett, fill_diagonal)

theano/tensor/extra_ops.py

@@ -3,8 +3,8 @@ import numpy
 
 import theano
 import basic
-from theano import gof, tensor, scalar
-from theano.sandbox.linalg.ops import diag
+from theano import gof, scalar
+import basic as tensor
 
 
 class DiffOp(theano.Op):
@@ -538,7 +538,9 @@ class FillDiagonal(gof.Op):
             raise NotImplementedError('%s: gradient is currently implemented'
                             ' for matrices only' % self.__class__.__name__)
         wr_a = fill_diagonal(grad, 0)  # valid for any number of dimensions
-        wr_val = diag(grad).sum()  # diag is only valid for matrices
+        # diag is only valid for matrices
+        import theano.sandbox.linalg
+        wr_val = theano.sandbox.linalg.ops.diag(grad).sum()
         return [wr_a, wr_val]