The context interface supports getting all signatures's input and output variables

paddlehub/module/module.py

@@ -451,7 +451,7 @@ class Module(object):
             raise ValueError("This Module is not callable!")
 
     def context(self,
-                sign_name,
+                sign_name=None,
                 for_test=False,
                 trainable=False,
                 regularizer=None,
@@ -463,10 +463,35 @@ class Module(object):
             available for BERT/ERNIE module
         """
 
-        if sign_name not in self.signatures:
-            raise KeyError(
-                "Module did not have a signature with name %s" % sign_name)
-        signature = self.signatures[sign_name]
+        if sign_name:
+            if sign_name not in self.signatures:
+                raise KeyError(
+                    "Module did not have a signature with name %s" % sign_name)
+            signature = self.signatures[sign_name]
+        else:
+            inputs = [
+                input for signature in self.signatures.values()
+                for input in signature.inputs
+            ]
+            outputs = [
+                output for signature in self.signatures.values()
+                for output in signature.outputs
+            ]
+            feed_names = [
+                feed_name for signature in self.signatures.values()
+                for feed_name in signature.feed_names
+            ]
+            fetch_names = [
+                fetch_name for signature in self.signatures.values()
+                for fetch_name in signature.fetch_names
+            ]
+            signature = create_signature(
+                name="hub_temp_signature",
+                inputs=inputs,
+                outputs=outputs,
+                feed_names=feed_names,
+                fetch_names=fetch_names,
+                for_predict=False)
 
         program = self.program.clone(for_test=for_test)
         paddle_helper.remove_feed_fetch_op(program)