code clean up

theano/gof/fg.py

@@ -341,7 +341,7 @@ class FunctionGraph(utils.object2):
                                 sio = StringIO()
                                 for subtr in tr:
                                     traceback.print_list(subtr, sio)
-                                    detailed_err_msg += str(sio.getvalue())
+                                detailed_err_msg += str(sio.getvalue())
                             raise MissingInputError(
                                 'A variable that is an input to the graph was '
                                 'neither provided as an input to the function '

theano/gof/link.py

@@ -165,7 +165,7 @@ def raise_with_op(node, thunk=None, exc_info=None, storage_map=None):
         sio = StringIO()
         for subtr in tr:
             traceback.print_list(subtr, sio)
-            detailed_err_msg += str(sio.getvalue())
+        detailed_err_msg += str(sio.getvalue())
     else:
         hints.append(
             "HINT: Re-running with most Theano optimization disabled could"

theano/gof/op.py

@@ -465,7 +465,7 @@ class PureOp(object):
                     sio = StringIO()
                     for subtr in tr:
                         traceback.print_list(subtr, sio)
-                        detailed_err_msg += str(sio.getvalue())
+                    detailed_err_msg += str(sio.getvalue())
 
                 detailed_err_msg += (
                     "\nThe error when converting the test value to that"

theano/tensor/opt.py

@@ -85,7 +85,7 @@ def copy_stack_trace(from_var, to_var):
         # If from_var is a list, store concatenated stack traces
         if len(from_var) > 0:
             for v in from_var:
-                if hasattr(v.tag, 'trace') and len(v.tag.trace) > 0:
+                if hasattr(v.tag, 'trace'):
                     tr = tr + v.tag.trace
     else:
         # If from_var is not a list, it must be a single tensor
@@ -98,17 +98,11 @@ def copy_stack_trace(from_var, to_var):
         # Copy over stack traces from from_var to each variable in
         # to_var, including the stack_trace of the to_var before
         for v in to_var:
-            if hasattr(v.tag, 'trace'):
-                v.tag.trace = v.tag.trace + tr
-            else:
-                v.tag.trace = tr
+            v.tag.trace = getattr(v.tag, 'trace', []) + tr
     else:
         # Copy over stack traces from from_var to each variable to
         # to_var, including the stack_trace of the to_var before
-        if hasattr(to_var.tag, 'trace'):
-            to_var.tag.trace = to_var.tag.trace + tr
-        else:
-            to_var.tag.trace = tr
+        to_var.tag.trace = getattr(to_var.tag, 'trace', []) + tr
 
 
 def out2in(*local_opts, **kwargs):