DataFrame.var(axis=None, skipna=None, level=None, ddof=1, numeric_only=None, **kwargs)

DataFrame.first_valid_index()

DataFrame.lt(other, axis='columns', level=None)

DataFrame.diff(periods=1, axis=0)

DataFrame.to_json(path_or_buf=None, orient=None, date_format='epoch', double_precision=10, force_ascii=True, date_unit='ms', default_handler=None

DataFrame.round(decimals=0, *args, **kwargs)

DataFrame.to_csv(path_or_buf=None, sep=', ', na_rep='', float_format=None, columns=None, header=True, index=True, index_label=None, mode='w'

DataFrame.iterrows()

DataFrame.rpow(other, axis='columns', level=None, fill_value=None)

DataFrame.radd(other, axis='columns', level=None, fill_value=None)