fix error message for Unsupported characters

Author: Neradoc

libraries/keyboard_layout.py

@@ -111,8 +111,8 @@ def _above128char_to_keycode(self, char):
             return self.HIGHER_ASCII[ord(char)]
 
         raise ValueError(
-            "Unsupported non-ASCII character {} \\x{}."
-            .format(str(char), ord(char))
+            "Unsupported non-ASCII character {letter} ({num}/0x{num:02x})."
+            .format(letter=str(char), num=ord(char))
         )
 
     def _char_to_keycode(self, char):
@@ -127,7 +127,7 @@ def _char_to_keycode(self, char):
         keycode = self.ASCII_TO_KEYCODE[char_val]
         if keycode == 0:
             raise ValueError(
-                "No keycode available for character {} \\x{}."
-                .format(str(char), char_val)
+                "No keycode available for character {letter} ({num}/0x{num:02x})."
+                .format(letter=str(char), num=char_val)
             )
         return keycode