Make sure we don't need to have pygpu installed to run theano.

theano/sandbox/gpuarray/basic_ops.py

@@ -7,8 +7,11 @@ from theano.scalar import Scalar
 
 from theano.gof.python25 import all, any
 
-import pygpu
-from pygpu import gpuarray, elemwise
+try:
+    import pygpu
+    from pygpu import gpuarray, elemwise
+except ImportError:
+    pass
 
 from type import GpuArrayType
 

theano/sandbox/gpuarray/elemwise.py

 import numpy
 from theano import Op, Apply, scalar
-from pygpu.tools import ScalarArg, ArrayArg
-from pygpu.elemwise import ElemwiseKernel
+
+try:
+    from pygpu.tools import ScalarArg, ArrayArg
+    from pygpu.elemwise import ElemwiseKernel
+except ImportError:
+    pass
 
 from basic_ops import as_gpuarray_variable
 from type import GpuArrayType

theano/sandbox/gpuarray/type.py

@@ -8,12 +8,10 @@ from theano.compile import SharedVariable
 # (it will not work though)
 try:
     import pygpu
-except ImportError:
-    pygpu = None
-
-if pygpu:
     from pygpu import gpuarray
     from pygpu.elemwise import compare, elemwise2
+except ImportError:
+    pass
 
 
 class GpuArrayType(Type):