replace ipynb magic

app.py

@@ -8,6 +8,7 @@
 
 import os
 import glob
+from shutil import rmtree
 from pathlib import Path
 from subprocess import run
 import json
@@ -44,9 +45,9 @@ n_models = len(rst_files)
 
 
 def fast_yolo_crop(image):
-    !rm -rf {working}/labels {working}/results_ensemble
-    #%cd {working}/yolov5
-    %cd {working}
+    rmtree(working / 'labels')
+    rmtree(working / 'results_ensemble')
+
     mpimg.imsave(yolo_source, image)
 
     #print(f"\nInference on best {len(checkpoint_files[5:])} models with detect.py ...")