trying to enable eidting of blank letter for entrance

parsers/caves.py

@@ -1,5 +1,6 @@
 import os
 import re
+import string
 
 
 from pathlib import Path
@@ -511,7 +512,9 @@ def read_cave(filename, cave=None):
             if len(entrances) > 1 and letter =="":
                 # user error, but we can recover
                 letter = eslug[-1].lower()
-                message = f"- Warning - duplicate entrance or empty 'letter' field for '{eslug}' in cave '{cave}', setting to {letter}."         
+                if letter.lower() not in list(string.ascii_lowercase):
+                    letter = "x"
+                message = f"- Warning - Empty 'letter' field for '{eslug}' in multiple-entrance cave '{cave}', setting to {letter}."         
                 DataIssue.objects.create(parser="entrances", message=message, url=f"{cave.area}/{cave.area}-{cave.url}_cave_edit/")
                 print(message)