Pandas массив в Python не сохраняется в csv

Есть простой код:

 import pandas as pd

 df = pd.read_csv('sample.csv')
 df.to_csv('result.csv')

Выходит ошибка при сохранения массива в csv:

----> 5 df.to_csv('result.csv')

/opt/conda/lib/python3.7/site-packages/pandas/core/generic.py in to_csv(self, path_or_buf, sep, na_rep, float_format, columns, header, index, index_label, mode, encoding, compression, quoting, quotechar, line_terminator, chunksize, date_format, doublequote, escapechar, decimal, errors)
   3143         if verify_is_copy:
   3144             self._check_setitem_copy(stacklevel=5, t='referant')
-> 3145 
   3146         if clear:
   3147             self._clear_item_cache()

/opt/conda/lib/python3.7/site-packages/pandas/io/formats/csvs.py in <module>
     14 
     15 from pandas._libs import writers as libwriters
---> 16 from pandas.compat import StringIO, range, zip
     17 
     18 from pandas.core.dtypes.generic import (

ImportError: cannot import name 'StringIO' from 'pandas.compat' (/opt/conda/lib/python3.7/site-packages/pandas/compat/__init__.py)