add id_to_class_name to dataset class

Author: wstmac

Diff for: datasets.py

@@ -36,6 +36,7 @@ def __init__(self, subset, base_cls, val_cls, support_cls, class_file_to_supercl
         # Convert arbitrary class names of dataset to ordered 0-(num_speakers - 1) integers
         self.unique_characters = sorted(self.df['class_name'].unique())
         self.class_name_to_id = {self.unique_characters[i]: i for i in range(self.num_classes())}
+        self.id_to_class_name = {self.class_name_to_id[key]:key for key in self.class_name_to_id.keys()}
         self.df = self.df.assign(class_id=self.df['class_name'].apply(lambda c: self.class_name_to_id[c]))
 
         # Create dicts