get rid of default context

contrib/Python/cntk/context.py

@@ -44,7 +44,7 @@ CNTK_OUTPUT_FILENAME = "out"
 _CONTEXT = {}
 
 
-def get_context(handle='default'):
+def get_context(handle):
     # TODO: we need more sanity in the model handling here
     if handle not in _CONTEXT:
         _CONTEXT[handle] = LocalExecutionContext(handle)
@@ -249,7 +249,7 @@ class AbstractContext(with_metaclass(ABCMeta, object)):
         tmpl_dict = {
             'ActionName': action_name,
             'ModelDescription': description,            
-            'Reader': input_map._to_config_description(),
+            'Reader': input_map._to_config_description(self.directory),
             'SGD': training_params._to_config_description(),
         }
 
@@ -282,7 +282,7 @@ class AbstractContext(with_metaclass(ABCMeta, object)):
 
         tmpl_dict = {
             'ActionName': action_name,
-            'Reader': input_map._to_config_description(),
+            'Reader': input_map._to_config_description(self.directory),
         }
         return "{0}\n{1}".format(g_params, tmpl % tmpl_dict)
 
@@ -310,7 +310,7 @@ class AbstractContext(with_metaclass(ABCMeta, object)):
         tmpl_dict = {
             'ActionName': action_name,
             'OutputFile': self.output_filename_base,
-            'Reader': input_map._to_config_description(),
+            'Reader': input_map._to_config_description(self.directory),
         }
         return "{0}\n{1}".format(g_params, tmpl % tmpl_dict)
 
@@ -355,7 +355,7 @@ class AbstractContext(with_metaclass(ABCMeta, object)):
             'NodeUnitTest': node_unit_test,
             'OutputFile': self.output_filename_base,
             'ModelDescription': description,
-            'Reader': input_map._to_config_description(),
+            'Reader': input_map._to_config_description(self.directory),
         }
         return "{0}\n{1}".format(g_params, tmpl % tmpl_dict)
 
@@ -423,7 +423,7 @@ class LocalExecutionContext(AbstractContext):
 
         if not output:
             raise ValueError('no output returned')
-
+        
         return output
 
     '''

contrib/Python/cntk/reader.py

@@ -493,7 +493,7 @@ class InputMap(object):
     def is_empty(self):
         return not self.has_mapped() and not self.has_unmapped()
 
-    def _to_config_description(self):
+    def _to_config_description(self, directory=None):
         if self.reader is None:
             if not self.unmapped_nodes:
                 # No inputs in the graph
@@ -504,8 +504,10 @@ class InputMap(object):
 
             from .context import get_context
             from .utils import get_temp_filename
-            filename = get_temp_filename(get_context().directory)
-
+            if not directory:
+                filename = get_temp_filename(get_context().directory)
+            else:
+                filename = get_temp_filename(directory)
             if len(self.node_map) > 0:
                 raise ValueError('you cannot have inputs initialized with '+
                         'NumPy arrays together with inputs that are ' +

contrib/Python/cntk/tests/reader_test.py

@@ -65,14 +65,3 @@ def test_serialize_unmapped_node(tmpdir):
 
     with open(tmpfile, 'r') as f:
         assert f.read() == expected
-
-def test_cntk_eval():
-
-    import cntk
-    import cntk.ops
-
-    result = cntk.eval(cntk.ops.floor([.4]))
-    np.allclose(result, [0])
-
-    result = cntk.eval(cntk.ops.floor([[.4]]))
-    np.allclose(result, [[0]])

contrib/Python/cntk/utils/eval.py

@@ -25,12 +25,12 @@ def eval(node):
         NumPy array containing the result
     """    
     
-    from cntk.context import get_context        
+    from cntk.context import get_new_context        
     from cntk.ops import input_numpy, constant
     from cntk.graph import ComputationNode
     
     # call a helper method to get a context
-    ctx = get_context()    
+    ctx = get_new_context()
     first = True    
     
     # The params are passed as arryas, e.g. plus([1,2], [3,4]),  and we need to