DataFrame.to_period(freq=None, axis=0, copy=True)

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

MultiIndex.has_duplicates

MultiIndex.duplicated(*args, **kwargs)

Series.dt.to_period(*args, **kwargs)

TimedeltaIndex.set_value(arr, key, value)

CategoricalIndex.sortlevel(level=None, ascending=True, sort_remaining=None)

CategoricalIndex.nlevels

Panel.pipe(func, *args, **kwargs)

Index.ndim return the number of dimensions of the underlying data, by definition 1