BUG: SparseDataFrame indexing may return normal Series by sinhrks · Pull Request #12787 · pandas-dev/pandas (original) (raw)

Found a below bug in SparseDataFrame indexing.

# NG, must be SparseSeries
df = pd.DataFrame([[1, 2], [np.nan, 4]]).to_sparse()
type(df.loc[0])  
# pandas.core.series.Series