Series.to_string(buf=None, na_rep='NaN', float_format=None, header=True, index=True, length=False, dtype=False, name=False, max_rows=None)

Series.data return the data pointer of the underlying data

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

Series.nunique(dropna=True)

Series.str.extract(pat, flags=0, expand=None)

Series.notnull()

Series.str.endswith(pat, na=nan)

Series.size return the number of elements in the underlying data

Series.dt.day The days of the datetime

Series.cat.add_categories(*args, **kwargs)