diff --git a/abl/framework_hed.py b/abl/framework_hed.py
index 76c57fa..c8d1e2a 100644
--- a/abl/framework_hed.py
+++ b/abl/framework_hed.py
@@ -52,9 +52,9 @@ def result_statistics(pred_Z, Z, Y, logic_forward, char_acc_flag):
 def filter_data(X, abduced_Z):
     finetune_Z = []
     finetune_X = []
-    for abduced_x, abduced_z in zip(X, abduced_Z):
-        if abduced_z is not []:
-            finetune_X.append(abduced_x)
+    for x, abduced_z in zip(X, abduced_Z):
+        if len(abduced_z) > 0:
+            finetune_X.append(x)
             finetune_Z.append(abduced_z)
     return finetune_X, finetune_Z
 
@@ -84,7 +84,6 @@ def train(model, abducer, train_data, test_data, epochs=50, sample_num=-1, verbo
     for epoch_idx in range(epochs):
         X, Z, Y = block_sample(train_X, train_Z, train_Y, sample_num, epoch_idx)
         preds_res = predict_func(X)
-        # input()
         abduced_Z = abduce_func(preds_res, Y)
 
         if ((epoch_idx + 1) % verbose == 0) or (epoch_idx == epochs - 1):