Series.eq(other, level=None, fill_value=None, axis=0)

DataFrame.query(expr, inplace=False, **kwargs)

DataFrame.sample(n=None, frac=None, replace=False, weights=None, random_state=None, axis=None)

pandas.read_fwf(filepath_or_buffer, colspecs='infer', widths=None, **kwds)

TimedeltaIndex.difference(other)

Series.align(other, join='outer', axis=None, level=None, copy=True, fill_value=None, method=None, limit=None, fill_axis=0, broadcast_axis=None)

Series.empty True if NDFrame is entirely empty [no items], meaning any of the axes are of length 0.

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

DatetimeIndex.has_duplicates

pandas.read_stata(filepath_or_buffer, convert_dates=True, convert_categoricals=True, encoding=None, index=None, convert_missing=False, preserve_dtypes=True