add deprecation warning.

test=develop

python/paddle/fluid/parallel_executor.py

@@ -92,6 +92,11 @@ class ParallelExecutor(object):
                  num_trainers=1,
                  trainer_id=0,
                  scope=None):
+        sys.stderr.write(
+            'ParallelExecutor is deprecated. '
+            'Please use CompiledProgram and Executor. CompiledProgram '
+            'is a central place for optimization and Executor is the '
+            'unified executor. Example can be found in compiler.py.\n')
         # step1: get places, the places are used in run too.
         self._places = []
         if use_cuda:

python/paddle/fluid/transpiler/inference_transpiler.py

@@ -15,6 +15,7 @@
 from __future__ import print_function
 
 import os
+import sys
 import numpy as np
 from .. import core
 from ..framework import Program
@@ -50,6 +51,7 @@ class InferenceTranspiler(object):
             place (Place): inference place
             scope (Scope|None): inference Scope
         '''
+        sys.stderr.write('InferenceTranspiler is deprecated.\n')
         if not isinstance(program, Program):
             raise TypeError("program should be as Program type")
         if not isinstance(place, core.CPUPlace) and not isinstance(

python/paddle/fluid/transpiler/memory_optimization_transpiler.py

@@ -15,6 +15,7 @@
 from __future__ import print_function
 
 import six
+import sys
 from collections import defaultdict, MutableSet
 from .. import core
 from ... import compat as cpt
@@ -509,6 +510,7 @@ def memory_optimize(input_program,
     Returns:
         None
     """
+    sys.stderr.write('memory_optimize is deprecated.\n')
 
     def to_name_str(var):
         if isinstance(var, Variable):