Studio: Create dataset ROI folder during export if it does not exist

slideflow/studio/widgets/roi.py

@@ -1,7 +1,8 @@
 import imgui
 import numpy as np
 import glfw
-from os.path import join
+import os
+from os.path import join, exists
 from shapely.geometry import Point
 from shapely.geometry import Polygon
 from tkinter.filedialog import askopenfilename
@@ -503,7 +504,10 @@ def draw_options(self):
 
         # Save button.
         if viz.sidebar.large_image_button('floppy', size=viz.font_size*3):
-            dest = viz.wsi.export_rois(self.get_roi_dest(viz.wsi.name))
+            roi_folder = self.get_roi_dest(viz.wsi.name)
+            if not exists(roi_folder):
+                os.makedirs(roi_folder)
+            dest = viz.wsi.export_rois()
             viz.create_toast(f'ROIs saved to {dest}', icon='success')
             self.reset_edit_state()
         if imgui.is_item_hovered():