use TowerHandle.get_tensor to access variables (fix #1409)

examples/DynamicFilterNetwork/steering-filter.py

@@ -12,6 +12,7 @@ from scipy.signal import convolve2d
 from tensorpack import *
 from tensorpack.dataflow import dataset
 from tensorpack.utils import logger
+from tensorpack.utils.gpu import change_gpu
 from tensorpack.utils.argtools import shape2d, shape4d
 from tensorpack.utils.viz import *
 

tensorpack/tfutils/tower.py

@@ -385,9 +385,9 @@ class TowerTensorHandle(object):
 
     def get_tensor(self, name):
         """
-        Get a tensor in this tower. The name can be:
+        Get a tensor in this tower. The name argument can be:
 
-        1. The name of the tensor without any tower prefix.
+        1. The name of a tensor/variable without any tower prefix.
 
         2. A name in the input signature, if it is used when building the tower.
 
@@ -405,7 +405,6 @@ class TowerTensorHandle(object):
         except KeyError:
             if name in self._extra_tensor_names:
                 return self._extra_tensor_names[name]
-            raise
         else:
             if name in self._extra_tensor_names:
                 mapped_tensor = self._extra_tensor_names[name]
@@ -415,6 +414,8 @@ class TowerTensorHandle(object):
                     " Assuming it is the input '{}'.".format(mapped_tensor.name))
                 return mapped_tensor
             return ret
+        # should also allow variables in get_tensor
+        return self.get_variable(name)
 
     def get_tensors(self, names):
         """