for k in range(1,nb_lines+1):
name = 'history_'+str(nb_lines-k+1)
self._dataframe[name] = [np.NaN]*k + list(self._dict_target.values())[:-k]
self._numerical_columns.append(name)
self._dataframe = self._dataframe[nb_lines:]
for k in range(1,nb_lines+1):
name = 'history_'+str(nb_lines-k+1)
self._dataframe[name] = [np.NaN]*k + list(self._dict_target.values())[:-k]
self._numerical_columns.append(name)
self._dataframe = self._dataframe[nb_lines:]