new_contents: # Copyright (c) 2018 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.
  """
  Print all signature of a python module in alphabet order.
  
  Usage:
      ./print_signature  "paddle.fluid" > signature.txt
  """
  import importlib
  import inspect
  import collections
  import sys
  import pydoc
  
  member_dict = collections.OrderedDict()
  
  
  def visit_member(parent_name, member):
      cur_name = ".".join([parent_name, member.__name__])
      if inspect.isclass(member):
          for name, value in inspect.getmembers(member):
              if hasattr(value, '__name__') and (not name.startswith("_") or
                                                 name == "__init__"):
                  visit_member(cur_name, value)
      elif callable(member):
          try:
              member_dict[cur_name] = inspect.getargspec(member)
          except TypeError:  # special for PyBind method
              member_dict[cur_name] = "  ".join([
                  line.strip() for line in pydoc.render_doc(member).split('\n')
                  if "->" in line
              ])
  
      else:
          raise RuntimeError("Unsupported generate signature of member, type {0}".
                             format(str(type(member))))
  
  
  def visit_all_module(mod):
      for member_name in (
              name
              for name in (mod.__all__ if hasattr(mod, "__all__") else dir(mod))
              if not name.startswith("_")):
          instance = getattr(mod, member_name, None)
          if instance is None:
              continue
          if inspect.ismodule(instance):
              visit_all_module(instance)
          else:
              visit_member(mod.__name__, instance)
  
  
  visit_all_module(importlib.import_module(sys.argv[1]))
  
  for name in member_dict:
      print name, member_dict[name]
  
subject: add print_signatures.py