Fix a few coding style

Author: yangarbiter

torchaudio/models/wavernn.py

@@ -17,7 +17,7 @@
 ]
 
 
-model_config_and_urls: Dict[str, Tuple[str, Dict[str, Any]]] = {
+_MODEL_CONFIG_AND_URLS: Dict[str, Tuple[str, Dict[str, Any]]] = {
     'wavernn_10k_epochs_8bits_ljspeech': (
         'https://download.pytorch.org/models/audio/wavernn_10k_epochs_8bits_ljspeech.pth',
         {
@@ -363,11 +363,11 @@ def get_pretrained_wavernn(checkpoint_name: str, progress: bool = True) -> WaveR
         checkpoint_name (str): The name of the checkpoint to load.
         progress (bool): If True, displays a progress bar of the download to stderr.
     """
-    if checkpoint_name in model_config_and_urls:
-        url, configs = model_config_and_urls[checkpoint_name]
-        model = WaveRNN(**configs)
-        state_dict = load_state_dict_from_url(url, progress=progress)
-        model.load_state_dict(state_dict)
-        return model
-    else:
-        raise ValueError("The model_name `{}` is not supported.".format(checkpoint_name))
+    if checkpoint_name not in _MODEL_CONFIG_AND_URLS:
+        raise ValueError("The checkpoint_name `{}` is not supported.".format(checkpoint_name))
+
+    url, configs = _MODEL_CONFIG_AND_URLS[checkpoint_name]
+    model = WaveRNN(**configs)
+    state_dict = load_state_dict_from_url(url, progress=progress)
+    model.load_state_dict(state_dict)
+    return model