问AttributeError：“”DataFrame“”对象没有属性“”target_name“”- scikit

EN

AttributeError                            Traceback (most recent call last)
<ipython-input-1-b1fbf288405a> in <module>()
     21 df.head(10)  #This should print 10 rows
     22 
---> 23 df.target_names
     24 df.feature_names
     25 

C:\Users\HP\Anaconda2\lib\site-packages\pandas\core\generic.pyc in __getattr__(self, name)
   3612             if name in self._info_axis:
   3613                 return self[name]
-> 3614             return object.__getattribute__(self, name)
   3615 
   3616     def __setattr__(self, name, value):

AttributeError: 'DataFrame' object has no attribute 'target_names'

import pandas as pd
import numpy as np
import matplotlib.pyplot as plt
from sklearn.decomposition import PCA
from sklearn import preprocessing

# create header for dataset
header = ['age','bp','sg','al','su','rbc','pc','pcc',
    'ba','bgr','bu','sc','sod','pot','hemo','pcv',
    'wbcc','rbcc','htn','dm','cad','appet','pe','ane',
    'classification']
# read the dataset
df = pd.read_csv("C:\Users\HP\Documents\machine learning project\Chronic_Kidney_Disease\chronic_kidney_disease_full.arff",
        header=None,
        names=header
       )
# dataset has '?' in it, convert these into NaN
df = df.replace('?', np.nan)
# drop the NaN
df = df.dropna(axis=0, how="any")
df.head(10)  #This should print 10 rows

df.target_names
df.feature_names