Fix pycuda import to remove tests error.

theano/misc/pycuda_init.py

@@ -41,17 +41,23 @@ if (not hasattr(theano.sandbox, 'cuda') or
             import pycuda.autoinit
             pycuda_available = True
 else:
-    import pycuda.driver
-    if hasattr(pycuda.driver.Context, "attach"):
-        pycuda.driver.Context.attach()
-    else:
-        # Now we always import this file when we call theano.sandbox.cuda.use
-        # So this should not happen normally.
-        # TODO: make this an error.
-        warnings.warn("For some unknow reason, theano.misc.pycuda_init was not"
-                      " imported before Theano initialized the GPU and"
-                      " your PyCUDA version is 2011.2.2 or earlier."
-                      " To fix the problem, import theano.misc.pycuda_init"
-                      " manually before using/initializing the GPU, use the"
-                      " Theano flag pycuda.init=True or use a"
-                      " more recent version of PyCUDA.")
+    try:
+        import pycuda.driver
+        pycuda_available = True
+    except ImportError:
+        pass
+    if pycuda_available:
+        if hasattr(pycuda.driver.Context, "attach"):
+            pycuda.driver.Context.attach()
+        else:
+            # Now we always import this file when we call
+            # theano.sandbox.cuda.use. So this should not happen
+            # normally.
+            # TODO: make this an error.
+            warnings.warn("For some unknow reason, theano.misc.pycuda_init was"
+                          " not imported before Theano initialized the GPU and"
+                          " your PyCUDA version is 2011.2.2 or earlier."
+                          " To fix the problem, import theano.misc.pycuda_init"
+                          " manually before using/initializing the GPU, use the"
+                          " Theano flag pycuda.init=True or use a"
+                          " more recent version of PyCUDA.")