Panel.filter(items=None, like=None, regex=None, axis=None)

Panel.at Fast label-based scalar accessor Similarly to loc, at provides label

class pandas.Series(data=None, index=None, dtype=None, name=None, copy=False, fastpath=False)

DatetimeIndex.to_perioddelta(freq)

StataReader.value_labels()

CategoricalIndex.to_series(**kwargs)

Series.map(arg, na_action=None)

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

DataFrame.stack(level=-1, dropna=True)

DataFrame.size number of elements in the NDFrame