Update app.py

app.py

@@ -11,8 +11,8 @@ def demo1_derive_MNIST_train_test_data():
     mnist = fetch_openml('mnist_784', version=1, as_frame=False)
     X, y = mnist["data"], mnist["target"]
     X_train, X_test, y_train, y_test = X[:60000], X[60000:], y[:60000], y[60000:]
-    y_train = y_train.astype(np.int) # convert to int
-    y_test = y_test.astype(np.int) # convert to int
+    y_train = y_train.astype(np.uint8) # convert to int
+    y_test = y_test.astype(np.uint8) # convert to int
     return X_train, X_test, y_train, y_test 
 
 X_train, X_test, y_train, y_test = demo1_derive_MNIST_train_test_data()