AttributeError                            Traceback (most recent call last)
<ipython-input-22-85f06d73187a> in <module>
      1 if __name__ == "__main__":
      2     datafile = "Train_Data35.csv"
----> 3     Create_Train_Data(datafile)
      4 
      5     train_data = Read_Train_Data(datafile)

<ipython-input-19-abdea8c259cb> in Create_Train_Data(datafile)
      1 def Create_Train_Data(datafile):
      2     mysetting = Settings()
----> 3     mu = mysetting.expect
      4     sigma = mysetting.variance
      5     num = mysetting.train_data_n

AttributeError: 'Settings' object has no attribute 'expect' 应该怎么改进呀