ValueError: Use .rename to alter labels with a mapper.

[chaichd]

This error occurs when I run the extract_episodes_from_subjects file，The error code is the last line below：

def read_itemid_to_variable_map(fn, variable_column='LEVEL2'):
var_map = dataframe_from_csv(fn, index_col=None).fillna('').astype(str)
var_map.COUNT = var_map.COUNT.astype(int)
var_map = var_map.loc[(var_map[variable_column] != '') & (var_map.COUNT > 0)]
var_map = var_map.loc[(var_map.STATUS == 'ready')]
var_map.ITEMID = var_map.ITEMID.astype(int)
var_map = var_map[[variable_column, 'ITEMID', 'MIMIC LABEL']].set_index('ITEMID')
return var_map.rename_axis({variable_column: 'VARIABLE', 'MIMIC LABEL': 'MIMIC_LABEL'}, axis=1)