python - “DataFrame”对象没有属性 'value_counts'

Question

我的数据集是维度为 (840,84) 的 DataFrame。当我写代码时:ds[ds.columns[1]].value_counts()
我得到了正确的输出:

Out[82]:
0    847
1      5
Name: o_East, dtype: int64

但是当我编写一个循环来存储值时，我得到“DataFrame”对象没有属性“value_counts”。我无法解释为什么......

wind_vec = []
wind_vec = [(ds[x].value_counts()) for x in ds.columns]

代码更新

import pandas as pd
import numpy as np
import numpy.ma as ma
import statsmodels.api as sm
import matplotlib
import matplotlib.pyplot as plt
from sklearn.preprocessing import OneHotEncoder

dataset = pd.read_csv('data/dataset.csv')

ds = dataset

o_wdire = pd.get_dummies(ds['o_wdire'])
s_wdire = pd.get_dummies(ds['s_wdire'])
t_wdire = pd.get_dummies(ds['t_wdire'])
k_wdire = pd.get_dummies(ds['k_wdire'])
b_wdire = pd.get_dummies(ds['b_wdire'])

o_wdire.rename(columns={'ENE': 'o_ENE','ESE': 'o_ESE', 'East': 'o_East', 'NE': 'o_NE', 'NNE': 'o_NNE', 'NNW': 'o_NNW', \
                     'NW': 'o_NW', 'North': 'o_North', 'SE': 'o_SE', 'SSE': 'o_SSE', 'SSW': 'o_SSW', 'SW': 'o_SW', \
                     'South': 'o_South', 'Variable': 'o_Variable', 'WSW': 'o_WSW','West':'o_West'}, inplace=True)
s_wdire.rename(columns={'ENE': 's_ENE','ESE': 's_ESE', 'East': 's_East', 'NE': 's_NE', 'NNE': 's_NNE', 'NNW': 's_NNW', \
                     'NW': 's_NW', 'North': 's_North', 'SE': 's_SE', 'SSE': 's_SSE', 'SSW': 's_SSW', 'SW': 's_SW', \
                     'South': 's_South', 'Variable': 's_Variable', 'West': 's_West','WSW': 's_WSW'}, inplace=True)
k_wdire.rename(columns={'ENE': 'k_ENE','ESE': 'k_ESE', 'East': 'k_East', 'NE': 'k_NE', 'NNE': 'k_NNE', 'NNW': 'k_NNW', \
                     'NW': 'k_NW', 'North': 'k_North', 'SE': 'k_SE', 'SSE': 'k_SSE', 'SSW': 'k_SSW', 'SW': 'k_SW', \
                     'South': 'k_South', 'Variable': 'k_Variable', 'WNW': 'k_WNW', 'West': 'k_West','WSW': 'k_WSW'}, inplace=True)
b_wdire.rename(columns={'ENE': 'b_ENE','ESE': 'b_ESE', 'East': 'b_East', 'NE': 'b_NE', 'NNE': 'b_NNE', 'NNW': 'b_NNW', \
                     'NW': 'b_NW', 'North': 'b_North', 'SE': 'b_SE', 'SSE': 'b_SSE', 'SSW': 'b_SSW', 'SW': 'b_SW', \
                     'South': 'b_South', 'Variable': 'b_Variable', 'WSW': 'b_WSW', 'WNW': 'b_WNW', 'West': 'b_West'}, inplace=True)
t_wdire.rename(columns={'ENE': 't_ENE','ESE': 't_ESE', 'East': 't_East', 'NE': 't_NE', 'NNE': 't_NNE', 'NNW': 't_NNW', \
                     'NW': 't_NW', 'North': 't_North', 'SE': 't_SE', 'SSE': 't_SSE', 'SSW': 't_SSW', 'SW': 't_SW', \
                     'South': 't_South', 'Variable': 't_Variable', 'WSW': 't_WSW', 'WNW': 't_WNW', 'West':'t_West'}, inplace=True)

#WIND
ds_wdire = pd.DataFrame(pd.concat([o_wdire,s_wdire,t_wdire,k_wdire,b_wdire],axis=1))
ds_wdire = ds_wdire.astype('float64')

In [93]: ds_wdire.shape
Out[93]: (852, 84)

In[101]: ds_wdire[ds_wdire.columns[0]].head()
Out[101]:   
0    0
1    0
2    0
3    0
4    0
Name: o_ENE, dtype: float64

In[103]: ds_wdire[ds_wdire.columns[0]].value_counts()
Out[103]:

0    838
1     14
Name: o_ENE, dtype: int64


In[104]: [ds_wdire[x].value_counts() for x in ds_wdire.columns]
---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
<ipython-input-104-d9756c468818> in <module>()
      1 #Filtering for the wind direction based on the most frequent ones.
----> 2 [ds_wdire[x].value_counts() for x in ds_wdire.columns]

<ipython-input-104-d9756c468818> in <listcomp>(.0)
      1 #Filtering for the wind direction based on the most frequent ones.
----> 2 [ds_wdire[x].value_counts() for x in ds_wdire.columns]

/home/florian/anaconda3/lib/python3.5/site-packages/pandas/core/generic.py in __getattr__(self, name)
   2358                 return self[name]
   2359             raise AttributeError("'%s' object has no attribute '%s'" %
-> 2360                                  (type(self).__name__, name))
   2361 
   2362     def __setattr__(self, name, value):

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

Answer 1

感谢@EdChum 的建议，我检查了:

len(ds_wdire.columns),len(ds_wdire.columns.unique())
Out[100]: (83,84)

实际上，字典中缺少一个名称值，应该将其从“WNW”修改为“o_WNW”。:

o_wdire.rename(columns={'ENE': 'o_ENE','ESE': 'o_ESE', 'East': 'o_East', 'NE': 'o_NE', 'NNE': 'o_NNE', 'NNW': 'o_NNW', \
                 'NW': 'o_NW', 'North': 'o_North', 'SE': 'o_SE', 'SSE': 'o_SSE', 'SSW': 'o_SSW', 'SW': 'o_SW', \
                 'South': 'o_South', 'Variable': 'o_Variable', 'WSW': 'o_WSW','West':'o_West', **[MISSING VALUE WNW]**}, inplace=True)

也许编写一个向风向变量插入前缀的循环会更好，这样我就可以避免此类问题。