def to_sparse(self, kind='<STR_LIT>', fill_value=None):
<EOL>from pandas.core.sparse.series import SparseSeries<EOL>values = SparseArray(self, kind=kind, fill_value=fill_value)<EOL>return SparseSeries(<EOL>values, index=self.index, name=self.name<EOL>).__finalize__(self)<EOL>
Convert Series to SparseSeries.

Parameters
----------
kind : {'block', 'integer'}, default 'block'
fill_value : float, defaults to NaN (missing)
    Value to use for filling NaN values.

Returns
-------
SparseSeries
    Sparse representation of the Series.