[utils] keep the original TV_PARENTAL_GUIDELINES dict

youtube_dl/utils.py

@@ -2253,12 +2253,12 @@ US_RATINGS = {
 
 
 TV_PARENTAL_GUIDELINES = {
-    'Y': 0,
+    'TV-Y': 0,
-    'Y7': 7,
+    'TV-Y7': 7,
-    'G': 0,
+    'TV-G': 0,
-    'PG': 0,
+    'TV-PG': 0,
-    '14': 14,
+    'TV-14': 14,
-    'MA': 17,
+    'TV-MA': 17,
 }
 
 
@@ -2272,9 +2272,9 @@ def parse_age_limit(s):
         return int(m.group('age'))
     if s in US_RATINGS:
         return US_RATINGS[s]
-    m = re.match(r'^TV[_-]?(%s)$' % '|'.join(TV_PARENTAL_GUIDELINES.keys()), s)
+    m = re.match(r'^TV[_-]?(%s)$' % '|'.join(k[3:] for k in TV_PARENTAL_GUIDELINES), s)
     if m:
-        return TV_PARENTAL_GUIDELINES[m.group(1)]
+        return TV_PARENTAL_GUIDELINES['TV-' + m.group(1)]
     return None