Use six.reraise for advanced exception raising.

theano/gof/cc.py

@@ -12,7 +12,7 @@ from itertools import izip
 import numpy
 
 from theano.compat import PY3
-from theano.compat.six import string_types
+from theano.compat.six import string_types, reraise
 from theano.compat.six.moves import StringIO, xrange
 from theano.gof.utils import MethodNotDefined
 
@@ -1537,8 +1537,7 @@ class _CThunk(object):
                                       ' Was the error set in the c code?'), end=' ', file=sys.stderr)
                 print(self.error_storage, file=sys.stderr)
                 raise
-
-            raise exc_type, exc_value, exc_trace
+            reraise(exc_type, exc_value, exc_trace)
 
 
 class OpWiseCLinker(link.LocalLinker):

theano/gof/link.py

@@ -7,6 +7,8 @@ import traceback
 import numpy
 
 import theano
+from theano.compat import PY3
+from theano.compat.six import reraise
 from theano.compat.six.moves import StringIO
 from theano.gof import utils
 from theano.gof import graph
@@ -100,7 +102,7 @@ def raise_with_op(node, thunk=None, exc_info=None, storage_map=None):
     exc_type, exc_value, exc_trace = exc_info
     if exc_type == KeyboardInterrupt:
         # print a simple traceback from KeyboardInterrupt
-        raise exc_type, exc_value, exc_trace
+        reraise(exc_type, exc_value, exc_trace)
     try:
         trace = node.outputs[0].tag.trace
     except AttributeError:
@@ -290,7 +292,7 @@ def raise_with_op(node, thunk=None, exc_info=None, storage_map=None):
 
     exc_value = exc_type(str(exc_value) + detailed_err_msg +
                          '\n' + '\n'.join(hints))
-    raise exc_type, exc_value, exc_trace
+    reraise(exc_type, exc_value, exc_trace)
 
 
 class Linker(object):

theano/gof/opt.py

@@ -942,10 +942,10 @@ def local_optimizer(tracks, inplace=False):
         """WRITEME"""
         if tracks is not None:
             if len(tracks) is 0:
-                raise ValueError, ("Use None instead of an empty list to apply to all nodes.", f.__module__, f.__name__)
+                raise ValueError("Use None instead of an empty list to apply to all nodes.", f.__module__, f.__name__)
             for t in tracks:
                 if not (isinstance(t, op.Op) or issubclass(t, op.PureOp)):
-                    raise ValueError, ("Tracks are op classes or instances", f.__module__, f.__name__)
+                    raise ValueError("Tracks are op classes or instances", f.__module__, f.__name__)
         requirements = ()
         if inplace:
             dh_handler = dh.DestroyHandler

theano/sandbox/debug.py

 from __future__ import print_function
 
+from theano.compat.six import reraise
 from theano import gof
 import sys
 
@@ -81,7 +82,7 @@ class DebugLinker(gof.WrapLinker):
                     exc.node = node
                     exc.thunk = thunk
                     exc.linker = linker
-                    raise DebugException, exc, exc_trace
+                    reraise(DebugException, exc, exc_trace)
 
     def compare_variables(self, i, node, *thunks):
         thunk0 = thunks[0]
@@ -146,7 +147,7 @@ class DebugLinker(gof.WrapLinker):
             exc.step = i
             exc.node = node
             exc.thunks = thunks
-            raise DebugException, exc, exc_trace
+            reraise(DebugException, exc, exc_trace)
 
 
 def print_info(i, node, *thunks):

theano/sandbox/gpuarray/basic_ops.py

@@ -73,7 +73,7 @@ class Kernel(object):
             elif isinstance(t, Variable):
                 return t.type.dtype
             else:
-                raise TypeError, "can't get a dtype from %s" % (type(t),)
+                raise TypeError("can't get a dtype from %s" % (type(t),))
         dtypes = [get_dtype(t) for t in types]
         flags = dict(cluda=True)
         if any(d == numpy.float64 for d in dtypes):
@@ -116,7 +116,7 @@ class GpuKernelBase(object):
         iterable of Kernel objects that describe the kernels this op
         will need.
         """
-        raise MethodNotDefined, 'gpu_kernels'
+        raise MethodNotDefined('gpu_kernels')
 
     def c_headers(self):
         try:

theano/sandbox/gpuarray/comp.py

@@ -40,9 +40,9 @@ class NVCC_compiler(NVCC_base):
         if not any(['-arch=sm_' in f for f in flags]):
             dev = theano.sandbox.gpuarray.init_dev.device
             if dev is None:
-                raise Exception, "Trying to compile GPU code without a context"
+                raise Exception("Trying to compile GPU code without a context")
             if dev.startswith("opencl"):
-                raise Exception, "Trying to call nvcc with an OpenCL context"
+                raise Exception("Trying to call nvcc with an OpenCL context")
             assert dev.startswith('cuda')
             if dev == 'cuda':
                 n = theano.sandbox.cuda.use.device_number