label encoding error

n_train, n_test, c_train, c_test = get_nc_data() # 데이터 새로 불러오기
from sklearn.preprocessing import LabelEncoder
le = LabelEncoder()

for col in cols  :
  le = LabelEncoder()
  c_train[col] = le.fit_transform(c_train[col])
  c_test[col] = le.transform(c_test[col])

이렇게 했는데, 

---------------------------------------------------------------------------
KeyError                                  Traceback (most recent call last)
/usr/local/lib/python3.10/dist-packages/pandas/core/indexes/base.py in get_loc(self, key)
   3804         try:
-> 3805             return self._engine.get_loc(casted_key)
   3806         except KeyError as err:

index.pyx in pandas._libs.index.IndexEngine.get_loc()

index.pyx in pandas._libs.index.IndexEngine.get_loc()

pandas/_libs/hashtable_class_helper.pxi in pandas._libs.hashtable.PyObjectHashTable.get_item()

pandas/_libs/hashtable_class_helper.pxi in pandas._libs.hashtable.PyObjectHashTable.get_item()

KeyError: 'age'

The above exception was the direct cause of the following exception:

KeyError                                  Traceback (most recent call last)
2 frames
/usr/local/lib/python3.10/dist-packages/pandas/core/indexes/base.py in get_loc(self, key)
   3810             ):
   3811                 raise InvalidIndexError(key)
-> 3812             raise KeyError(key) from err
   3813         except TypeError:
   3814             # If we have a listlike key, _check_indexing_error will raise

KeyError: 'age'

age와 관련된 이상한 오류가 뜨네요...