add comments and type hints

src/coastseg/coastseg_map.py

@@ -118,7 +118,7 @@ def find_shorelines_directory(path, roi_id):
     return None
 
 
-def delete_extracted_shorelines_files(session_path, selected_items):
+def delete_extracted_shorelines_files(session_path:str, selected_items:List):
     """Delete the extracted shorelines from the session directory for all the relevant files
     Removes the extracted shorelines from the following files:
     - extracted_shorelines_lines.geojson
@@ -164,7 +164,7 @@ def delete_extracted_shorelines_files(session_path, selected_items):
     file_patterns = ["_timeseries_tidally_corrected", "_timeseries_raw.csv"]
     for file_pattern in file_patterns:
         common.drop_rows_from_csv(file_pattern, session_path, dates_list)
-    # delete the extracted shorelines from the jpg deterction files
+    # delete the extracted shorelines from the jpg detection files
     jpg_path = os.path.join(session_path, "jpg_files", "detection")
     if os.path.exists(jpg_path) and os.path.isdir(jpg_path):
         common.delete_jpg_files(dates_list, sat_list, jpg_path)

src/coastseg/common.py

@@ -212,7 +212,9 @@ def update_extracted_shorelines_dict_transects_dict(
 ):
     json_file = os.path.join(session_path, filename)
     if os.path.exists(json_file) and os.path.isfile(json_file):
+        # read the data from the json file 
         data = file_utilities.load_data_from_json(json_file)
+        # processes the data into nested arrays
         extracted_shorelines_dict = process_data_input(data)
         if extracted_shorelines_dict is not None:
             # Get the indexes of the selected items in the extracted_shorelines_dict
@@ -223,6 +225,7 @@ def update_extracted_shorelines_dict_transects_dict(
             transect_cross_distances_path = os.path.join(
                 session_path, "transects_cross_distances.json"
             )
+            # if the transect_cross_distances.json exists then delete the selected indexes from it
             if os.path.exists(transect_cross_distances_path) and os.path.isfile(
                 transect_cross_distances_path
             ):