Update mammography.py

mammography.py

@@ -105,7 +105,10 @@ class Mammography(datasets.GeneratorBasedBuilder):
         data.columns = _ORIGINAL_FEATURE_NAMES
         
         data.drop("rads", axis="columns", inplace=True)
-        data = data[(data.age != "?") & (data.shape != "?") & (data.margin != "?") & (data.density != "?")]
+        data = data[data.age != "?"]
+        data = data[data.shape != "?"]
+        data = data[data.margin != "?"]
+        data = data[data.density != "?"]
         data = data.infer_objects()
         for feature in _ENCODING_DICS:
             print(feature)