Teste Wilcoxon - Erro no código

Até a linha anterior funcionou igual ao da aula. Mas o código seguinte não funciona.

fumo.drop(['Posto'], axis = 1, inplace = True)

---------------------------------------------------------------------------
KeyError                                  Traceback (most recent call last)
<ipython-input-281-9eddec9def52> in <module>
----> 1 fumo.drop(["Posto"], axis = 1 , inplace = True)

~\anaconda3\lib\site-packages\pandas\core\frame.py in drop(self, labels, axis, index, columns, level, inplace, errors)
   4306                 weight  1.0     0.8
   4307         """
-> 4308         return super().drop(
   4309             labels=labels,
   4310             axis=axis,

~\anaconda3\lib\site-packages\pandas\core\generic.py in drop(self, labels, axis, index, columns, level, inplace, errors)
   4151         for axis, labels in axes.items():
   4152             if labels is not None:
-> 4153                 obj = obj._drop_axis(labels, axis, level=level, errors=errors)
   4154 
   4155         if inplace:

~\anaconda3\lib\site-packages\pandas\core\generic.py in _drop_axis(self, labels, axis, level, errors)
   4186                 new_axis = axis.drop(labels, level=level, errors=errors)
   4187             else:
-> 4188                 new_axis = axis.drop(labels, errors=errors)
   4189             result = self.reindex(**{axis_name: new_axis})
   4190 

~\anaconda3\lib\site-packages\pandas\core\indexes\base.py in drop(self, labels, errors)
   5589         if mask.any():
   5590             if errors != "ignore":
-> 5591                 raise KeyError(f"{labels[mask]} not found in axis")
   5592             indexer = indexer[~mask]
   5593         return self.delete(indexer)

KeyError: "['Posto'] not found in axis"