如何标记数据集表中的列索引？

Question

我正在尝试标记编码第二列我收到错误。我究竟做错了什么？我能够编码第一列

    data.head()
        area_type   availability    location    size    society total_sqft  bath    balcony price
    0   Super built-up Area 19-Dec  Electronic City Phase II    2 BHK   Coomee  1056    2.0 1.0 39.07
    1   Plot Area   Ready To Move   Chikka Tirupathi    4 Bedroom   Theanmp 2600    5.0 3.0 120.00
    2   Built-up Area   Ready To Move   Uttarahalli 3 BHK   NaN 1440    2.0 3.0 62.00
    3   Super built-up Area Ready To Move   Lingadheeranahalli  3 BHK   Soiewre 1521    3.0 1.0 95.00
    4   Super built-up Area Ready To Move   Kothanur    2 BHK   NaN 1200    2.0 1.0 51.00
enc = LabelEncoder()
data.iloc[:,2] = enc.fit_transform(data.iloc[:,2])
---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-20-53fda4a71b5e> in <module>()
      1 enc = LabelEncoder()
----> 2 data.iloc[:,2] = enc.fit_transform(data.iloc[:,2])

~/anaconda3/lib/python3.6/site-packages/sklearn/preprocessing/label.py in fit_transform(self, y)
    110         """
    111         y = column_or_1d(y, warn=True)
--> 112         self.classes_, y = np.unique(y, return_inverse=True)
    113         return y
    114 

~/anaconda3/lib/python3.6/site-packages/numpy/lib/arraysetops.py in unique(ar, return_index, return_inverse, return_counts, axis)
    208     ar = np.asanyarray(ar)
    209     if axis is None:
--> 210         return _unique1d(ar, return_index, return_inverse, return_counts)
    211     if not (-ar.ndim <= axis < ar.ndim):
    212         raise ValueError('Invalid axis kwarg specified for unique')

~/anaconda3/lib/python3.6/site-packages/numpy/lib/arraysetops.py in _unique1d(ar, return_index, return_inverse, return_counts)
    272 
    273     if optional_indices:
--> 274         perm = ar.argsort(kind='mergesort' if return_index else 'quicksort')
    275         aux = ar[perm]
    276     else:

TypeError: '<' not supported between instances of 'float' and 'str'

我想标记编码第二列“位置”，如果我使用data.iloc[:,1] = enc.fit_transform(data.iloc[:,1])索引我可以标记编码可用性列，那么我该如何解决这个问题？

Answer 1

列的数据类型是什么？

出现错误是因为标签编码器无法对数字（以及np.nan是浮点数）和字符串进行排序。

要解决这个问题，您可以： - 用空字符串data['col_name'].fillna('',inplace=True)替换任何nan; - 通过键入data['col_name'] = data['col_name'].astype(str)将列转换为字符串