调用类的方法时未实现错误

Question

当我尝试调用类的方法时遇到此错误。我不知道我要去哪里哪里

class KickstarterModel:

    def __init__(self):

        self.model = DecisionTreeClassifier()
        self.X_train = None
        self.y_train = None


    def preprocess_training_data(self, df):

        y_train = df['state'].apply(lambda x: 0 if x == 'failed' else 1)

        numerical_columns = df.describe().columns
        X = df[numerical_columns].copy()
        X.set_index('id', inplace=True)

        X["dif_launched_created"] = X.launched_at - X.created_at
        X["dif_deadline_created"] = X.deadline - X.created_at
        X["dif_deadline_launched"] = X.deadline - X.launched_at
        X['goal_in_usd'] = X.goal * X.static_usd_rate

        X.drop(['deadline', 'created_at', 'launched_at', 'goal', 'static_usd_rate'], axis=1, inplace=True)

        X_train = X
        y_train = y

错误消息：

NotImplementedError                       
Traceback (most recent call last)
<ipython-input-25-18acf6b32d72> in <module>()
      1 model = KickstarterModel()
      2 
----> 3 model.preprocess_training_data(df)

~\OneDrive\Documents\Cambridge Spark\Module 3\model.py in preprocess_training_data(self, df)
      7         self.y_train = None
      8 
----> 9 
     10     def preprocess_training_data(self, df):
     11 

NotImplementedError: