allow .- in id

utils.py

@@ -41,7 +41,7 @@ def get_id_prefix_from_string(s):
     first_illegal_char_index = 0
     for i, c in enumerate(s.replace(' ', '')):
         first_illegal_char_index = i
-        if c not in 'QWERTYUIOPASDFGHJKLZXCVBNM1234567890qwertyuiopasdfghjklzxcvbnm':
+        if c not in 'QWERTYUIOPASDFGHJKLZXCVBNM1234567890qwertyuiopasdfghjklzxcvbnm.-':
             break
     return s[:first_illegal_char_index]