Update app.py

app.py

@@ -55,8 +55,8 @@ utils_ops.tf = tf.compat.v1
 
 # Patch the location of gfile
 tf.gfile = tf.io.gfile
-os.system('cd ..')
-os.system('python object_detection/builders/model_builder_tf2_test.py')
+os.chdir('..')
+os.system('python research/object_detection/builders/model_builder_tf2_test.py')
 def load_model(model_dir):
   model = tf.saved_model.load(str(model_dir))
   model = model.signatures['serving_default']