Исключение: данные должны быть одномерными при создании фрейма данных из списка

Question

Я пытаюсь создать датафрейм из списков и получаю следующее исключение:

Исключение: данные должны быть одномерными

project_transformed_data = pd.DataFrame(data = {'school_state':school_state,
                                                'grade_one_hot':grade_one_hot,
                                                'teacher_prefix':teacher_prefix,
                                                'categories_one_hot':categories_one_hot,
                                                'sub_categories_one_hot':sub_categories_one_hot,
                                                'price_standardized':price_standardized,
                                                'quantity_standardized':quantity_standardized,
                                                'no_project_standardized':no_project_standardized,
                                                'preprocessed_essays':preprocessed_essays,
                                                'preprocessed_title':preprocessed_title,
                                                'preprocessed_resource_description':preprocessed_resource_description
                                               })

Полная трассировка исключений:

Exception                                 Traceback (most recent call last)

<ipython-input-42-534fb60e58d6> in <module>()
      9                                                 'preprocessed_essays':preprocessed_essays,
     10                                                 'preprocessed_title':preprocessed_title,
---> 11                                                 'preprocessed_resource_description':preprocessed_resource_description
     12                                                })

/usr/local/lib/python3.6/dist-packages/pandas/core/frame.py in __init__(self, data, index, columns, dtype, copy)
    328                                  dtype=dtype, copy=copy)
    329         elif isinstance(data, dict):
--> 330             mgr = self._init_dict(data, index, columns, dtype=dtype)
    331         elif isinstance(data, ma.MaskedArray):
    332             import numpy.ma.mrecords as mrecords

/usr/local/lib/python3.6/dist-packages/pandas/core/frame.py in _init_dict(self, data, index, columns, dtype)
    459             arrays = [data[k] for k in keys]
    460 
--> 461         return _arrays_to_mgr(arrays, data_names, index, columns, dtype=dtype)
    462 
    463     def _init_ndarray(self, values, index, columns, dtype=None, copy=False):

/usr/local/lib/python3.6/dist-packages/pandas/core/frame.py in _arrays_to_mgr(arrays, arr_names, index, columns, dtype)
   6166 
   6167     # don't force copy because getting jammed in an ndarray anyway
-> 6168     arrays = _homogenize(arrays, index, dtype)
   6169 
   6170     # from BlockManager perspective

/usr/local/lib/python3.6/dist-packages/pandas/core/frame.py in _homogenize(data, index, dtype)
   6475                 v = lib.fast_multiget(v, oindex.values, default=np.nan)
   6476             v = _sanitize_array(v, index, dtype=dtype, copy=False,
-> 6477                                 raise_cast_failure=False)
   6478 
   6479         homogenized.append(v)

/usr/local/lib/python3.6/dist-packages/pandas/core/series.py in _sanitize_array(data, index, dtype, copy, raise_cast_failure)
   3273     elif subarr.ndim > 1:
   3274         if isinstance(data, np.ndarray):
-> 3275             raise Exception('Data must be 1-dimensional')
   3276         else:
   3277             subarr = _asarray_tuplesafe(data, dtype=dtype)

Exception: Data must be 1-dimensional

preprocessed_resource_description - это список. Тем не менее я получаю исключение.

Любая идея, почему я получаю это исключение.

Пример данных:

print(preprocessed_resource_description[0:2])
print(type(preprocessed_resource_description))
print(len(preprocessed_resource_description))

Выход:

['kids kore wobble chair 14 blackreading tree classroom rug shape rectangle rug dimensions 7 8 w x 10 9 lseat foam pad blackjack chair purple cotton', 'robot mouse stem activity set']
<class 'list'>
20000