Update mushroom.py

mushroom.py

@@ -312,7 +312,8 @@ class Mushroom(datasets.GeneratorBasedBuilder):
     def preprocess(self, data: pandas.DataFrame, config: str = DEFAULT_CONFIG) -> pandas.DataFrame:     
         data.columns = _ORIGINAL_FEATURE_NAMES
         print(data.columns)
-        data.drop("stalk_root", axis="columns", inplace=True)
+        if "stalk_root" in data.columns:
+            data.drop("stalk_root", axis="columns", inplace=True)
         data = data[features_types_per_config[config].keys()]
 
         for feature in _ENCODING_DICS: