Fixed error in opt local_sum_prod_mul_by_scalar. Also fixed flake8 errors.

theano/tensor/opt.py

@@ -4602,7 +4602,6 @@ def local_fill_cut(node):
     # from the removed fill op, it must come from the elemntwise op.
     copy_stack_trace(node.outputs, rval)
 
-
     if isinstance(rval, gof.Variable):
         return rval.owner.outputs
     else:
@@ -5190,7 +5189,7 @@ def local_sum_prod_mul_by_scalar(node):
                 ret = T.mul(*mul_inputs)
                 # Copy over stacktrace from previous output to new mul op,
                 # for same reason as above.
-                copy_stack_trace(node.outputs, ret+mul_inputs)
+                copy_stack_trace(node.outputs,[ret]+mul_inputs)
 
                 return [ret]
 

theano/tensor/tests/test_opt.py

@@ -3677,7 +3677,6 @@ class Test_local_useless_elemwise_comparison(unittest.TestCase):
         self.assert_eqs_const(f, 0, op=T.alloc)
         assert (f([3, 3]) == 0).all()
 
- 
     def test_and(self):
         mode = theano.compile.get_default_mode().including('canonicalize')
 
@@ -3724,7 +3723,6 @@ class Test_local_useless_elemwise_comparison(unittest.TestCase):
         f = theano.function([x], T.xor(x, x), mode=mode)
         self.assert_eqs_const(f, 0)
 
-
     def test_stacktrace(self):
         mode = theano.compile.get_default_mode().including(
             'local_useless_elemwise_comparison')
@@ -6310,7 +6308,7 @@ class Test_local_useless_reshape(unittest.TestCase):
 
         # TODO: Check that stack trace is maintained.
         #       Currently, stack trace gets removed by some other opt.
-        #assert check_stack_trace(f1, ops_to_check='all')
+        #       assert check_stack_trace(f1, ops_to_check='all')
 
         m2 = m0.excluding('local_useless_reshape')
 
@@ -6331,7 +6329,7 @@ class Test_local_useless_reshape(unittest.TestCase):
 
         # TODO: Check that stack trace is maintained.
         #       Currently, stack trace gets removed by some other opt.
-        #assert check_stack_trace(f1, ops_to_check='all')
+        #       assert check_stack_trace(f1, ops_to_check='all')
 
         m2 = m1.excluding('ShapeOpt')
         f2 = theano.function([x], r, mode=m2)
@@ -6385,6 +6383,7 @@ def test_local_reshape_lift():
     # Check stacktrace was copied over correctly after opt was applied
     assert check_stack_trace(f, ops_to_check='last')
 
+
 class Test_lift_transpose_through_dot(unittest.TestCase):
     def simple_optimize(self, g):
         out2in(opt.local_useless_elemwise).optimize(g)