[utils] Add dict_get convenience method

youtube_dl/utils.py

@@ -1717,6 +1717,15 @@ def encode_dict(d, encoding='utf-8'):
     return dict((encode(k), encode(v)) for k, v in d.items())
 
 
+def dict_get(d, key_or_keys, default=None):
+    if isinstance(key_or_keys, (list, tuple)):
+        for key in key_or_keys:
+            if d.get(key):
+                return d[key]
+        return default
+    return d.get(key_or_keys, default)
+
+
 def encode_compat_str(string, encoding=preferredencoding(), errors='strict'):
     return string if isinstance(string, compat_str) else compat_str(string, encoding, errors)