Merge pull request #7816 from wanghaoshuang/infer_prog

 Make get_inference_program support for Evaluator.

Author: wanghaoshuang

python/paddle/v2/fluid/io.py

@@ -15,6 +15,7 @@
 import os
 import cPickle as pickle
 
+from paddle.v2.fluid.evaluator import Evaluator
 from paddle.v2.fluid.framework import Program, Parameter, default_main_program, Variable
 from . import core
 
@@ -187,8 +188,14 @@ def get_inference_program(target_vars, main_program=None):
         main_program = default_main_program()
     if not isinstance(target_vars, list):
         target_vars = [target_vars]
-
-    pruned_program = main_program.prune(targets=target_vars)
+    vars = []
+    for var in target_vars:
+        if isinstance(var, Evaluator):
+            vars.append(var.states)
+            vars.append(var.metrics)
+        else:
+            vars.append(var)
+    pruned_program = main_program.prune(targets=vars)
     inference_program = pruned_program.inference_optimize()
     return inference_program