Mgiyuk

How to fill nan values with an expression please make an effort trying to help me to know how to fill nan values with a certain expression. If NaN value is True, I want to replace by the substrac of two dates to obtain the days between the dates. Table: Nan - 24/05/2017 - 25/05/2017 Nan - 24/06/2018 - 25/06/2018 35 - 10/03/2017 - 5/04/2017 I want to obtain 1 - 24/05/2017 - 25/05/2017 1 - 24/06/2018 - 25/06/2018 35 - 10/03/2017 - 5/04/2017 Please help. Im trying to do with: dfp['DIAS A ULTIMO SINIESTRO'] = dfp['DIAS A ULTIMO SINIESTRO'].fillna(value=np.where(dfp['ESTADO']==1,(dfp['FECHA_ANULACION']-dfp['FECHA_INI_VIGENCIA']).dt.days,(dfp['FECHA_FIN_VIGENCIA']-dfp['FECHA_INI_VIGENCIA']).dt.days)) But I obtain this error: ValueError: invalid fill value with a class 'numpy.ndarray' By clicking "Post Your Answer", you acknowledge that you have read ou...