Automatically generated doc string for generated layers (#5585)

python/paddle/v2/framework/layers.py

 import paddle.v2.framework.core as core
+import paddle.v2.framework.proto.framework_pb2 as framework_pb2
 from paddle.v2.framework.framework import OpProtoHolder, Variable, Program, \
     Operator
 from paddle.v2.framework.initializer import ConstantInitializer, \
     NormalInitializer
 from paddle.v2.framework.layer_helper import LayerHelper, unique_name
 import re
+import cStringIO
 
 __all__ = [
     'fc', 'data', 'cross_entropy', 'conv2d', 'pool2d', 'embedding', 'concat',
@@ -240,6 +242,58 @@ def _convert_(name):
     return re.sub('([a-z0-9])([A-Z])', r'\1_\2', s1).lower()
 
 
+def _generate_doc_string_(op_proto):
+    """
+    Generate docstring by OpProto
+    
+    Args:
+        op_proto (framework_pb2.OpProto): a protobuf message typed OpProto
+
+    Returns:
+        str: the document string
+    """
+
+    def _type_to_str_(tp):
+        return framework_pb2.AttrType.Name(tp)
+
+    if not isinstance(op_proto, framework_pb2.OpProto):
+        raise TypeError("OpProto should be `framework_pb2.OpProto`")
+
+    buf = cStringIO.StringIO()
+    buf.write(op_proto.comment)
+    buf.write('\nArgs:\n')
+    for each_input in op_proto.inputs:
+        line_begin = '    {0}: '.format(_convert_(each_input.name))
+        buf.write(line_begin)
+        buf.write(each_input.comment)
+        buf.write('\n')
+        buf.write(' ' * len(line_begin))
+        buf.write('Duplicable: ')
+        buf.write(str(each_input.duplicable))
+        buf.write('  Optional: ')
+        buf.write(str(each_input.dispensable))
+        buf.write('\n')
+
+    for each_attr in op_proto.attrs:
+        buf.write('    ')
+        buf.write(each_attr.name)
+        buf.write(' (')
+        buf.write(_type_to_str_(each_attr.type))
+        buf.write('): ')
+        buf.write(each_attr.comment)
+        buf.write('\n')
+
+    if len(op_proto.outputs) != 0:
+        buf.write('\nReturns:\n')
+        buf.write('    ')
+        for each_opt in op_proto.outputs:
+            if not each_opt.intermediate:
+                break
+        buf.write(each_opt.comment)
+
+    return buf.getvalue()
+
+
 def _create_op_func_(op_type):
     """
     Create an Operator for a Function.
@@ -298,11 +352,6 @@ def _create_op_func_(op_type):
         return dtype
 
     def func(**kwargs):
-        """
-        This function implements the function for the operator. This process
-        involves doing the sanity check (using the function above), reading
-        inputs from protobuf and applying the activations on top.
-        """
         helper = LayerHelper(op_type, **kwargs)
 
         dtype = infer_and_check_data_type(op_proto, **kwargs)
@@ -326,6 +375,7 @@ def _create_op_func_(op_type):
 
     func.__name__ = op_type
     globals()[op_type] = func
+    func.__doc__ = _generate_doc_string_(op_proto)
     global __all__
     __all__.append(op_type)
 

python/paddle/v2/framework/tests/test_create_op_doc_string.py

+import unittest
+import paddle.v2.framework.layers as layers
+
+
+class TestDocString(unittest.TestCase):
+    def test_layer_doc_string(self):
+        print layers.dropout.__doc__
+
+
+if __name__ == '__main__':
+    unittest.main()