fix init_metrics and prune (#2153)

dygraph/ppdet/engine/trainer.py

@@ -110,6 +110,9 @@ class Trainer(object):
             self._compose_callback = None
 
     def _init_metrics(self):
+        if self.mode == 'test':
+            self._metrics = []
+            return
         if self.cfg.metric == 'COCO':
             self._metrics = [COCOMetric(anno_file=self.dataset.get_anno())]
         elif self.cfg.metric == 'VOC':

dygraph/ppdet/slim/prune.py

@@ -49,6 +49,9 @@ class Pruner(object):
         self.print_params = print_params
 
     def __call__(self, model):
+        # FIXME: adapt to network graph when Training and inference are
+        # inconsistent, now only supports prune inference network graph.
+        model.eval()
         paddleslim = try_import('paddleslim')
         from paddleslim.analysis import dygraph_flops as flops
         input_spec = [{