add signature class and method

paddle_hub/signature.py

+#   Copyright (c) 2019  PaddlePaddle Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from __future__ import absolute_import
+from __future__ import division
+from __future__ import print_function
+from paddle.fluid.framework import Variable
+from paddle_hub.utils import to_list
+
+
+class Signature:
+    def __init__(self, name, inputs, outputs):
+        self.name = name
+        inputs = to_list(inputs)
+        outputs = to_list(outputs)
+
+        for item in inputs:
+            assert isinstance(
+                item,
+                Variable), "the item of inputs list shoule be paddle Variable"
+
+        for item in outputs:
+            assert isinstance(
+                item,
+                Variable), "the item of outputs list shoule be paddle Variable"
+
+        self.inputs = inputs
+        self.outputs = outputs
+
+    def get_name(self):
+        return self.name
+
+    def get_inputs(self):
+        return self.inputs
+
+    def get_outputs(self):
+        return self.outputs
+
+
+def create_signature(name="defalut", inputs=[], outputs=[]):
+
+    return Signature(name=name, inputs=inputs, outputs=outputs)