diff --git a/modules/deeplearning/cnn_cld_frac.py b/modules/deeplearning/cnn_cld_frac.py
index 6db426732a4784135da9631bf014ef8502033b30..a01a81924acd32a1c3d7b2457187e98a8b1afbaa 100644
--- a/modules/deeplearning/cnn_cld_frac.py
+++ b/modules/deeplearning/cnn_cld_frac.py
@@ -314,7 +314,7 @@ class CNN:
     def get_label_data(self, grd_k):
         num, leny, lenx = grd_k.shape
         grd_down_2x = np.zeros((num, leny, lenx))
-        for t in range(len(num)):
+        for t in range(num):
             for j in range(int(leny / 2)):
                 for i in range(int(lenx / 2)):
                     cell = grd_k[t, j:j + 2, i:i + 2]