[Dygraph] fix load_weight and no bbox output (#2135)

* fix load_weight and no bbox output

dygraph/ppdet/modeling/post_process.py

@@ -50,7 +50,9 @@ class BBoxPostProcess(object):
                                including labels, scores and bboxes. The size of
                                bboxes are corresponding to the original image.
         """
-        assert bboxes.shape[0] > 0, 'There is no detection output'
+        if bboxes.shape[0] == 0:
+            return paddle.to_tensor([[0, 0.0, 0.0, 0.0, 0.0, 0.0]])
+
         origin_shape = paddle.floor(im_shape / scale_factor + 0.5)
 
         origin_shape_list = []

dygraph/ppdet/utils/checkpoint.py

@@ -91,7 +91,25 @@ def load_weight(model, weight, optimizer=None):
                          "exists.".format(pdparam_path))
 
     param_state_dict = paddle.load(pdparam_path)
-    model.set_dict(param_state_dict)
+    model_dict = model.state_dict()
+
+    model_weight = {}
+    incorrect_keys = 0
+
+    for key in model_dict.keys():
+        if key in param_state_dict.keys():
+            model_weight[key] = param_state_dict[key]
+        else:
+            logger.info('Unmatched key: {}'.format(key))
+            incorrect_keys += 1
+
+    assert incorrect_keys == 0, "Load weight {} incorrectly, \
+            {} keys unmatched, please check again.".format(weight,
+                                                           incorrect_keys)
+    logger.info('Finish loading model weight parameter: {}'.format(
+        pdparam_path))
+
+    model.set_dict(model_weight)
 
     last_epoch = 0
     if optimizer is not None and os.path.exists(path + '.pdopt'):