Fixes SparseSeries initiated with dictionary raising AttributeError (#…

…16960)

doc/source/whatsnew/v0.21.0.txt

@@ -219,7 +219,7 @@ Groupby/Resample/Rolling
 
 Sparse
 ^^^^^^
-
+- Bug in ``SparseSeries`` raises ``AttributeError`` when a dictionary is passed in as data (:issue:`16777`)
 
 
 Reshaping

pandas/core/sparse/series.py

@@ -146,10 +146,9 @@ def __init__(self, data=None, index=None, sparse_index=None, kind='block',
                 data = data._data
 
             elif isinstance(data, (Series, dict)):
-                if index is None:
-                    index = data.index.view()
+                data = Series(data, index=index)
+                index = data.index.view()
 
-                data = Series(data)
                 res = make_sparse(data, kind=kind, fill_value=fill_value)
                 data, sparse_index, fill_value = res
 

pandas/tests/sparse/test_series.py

@@ -88,6 +88,24 @@ def setup_method(self, method):
         self.ziseries2 = SparseSeries(arr, index=index, kind='integer',
                                       fill_value=0)
 
+    def test_constructor_dict_input(self):
+        # gh-16905
+        constructor_dict = {1: 1.}
+        index = [0, 1, 2]
+
+        # Series with index passed in
+        series = pd.Series(constructor_dict)
+        expected = SparseSeries(series, index=index)
+
+        result = SparseSeries(constructor_dict, index=index)
+        tm.assert_sp_series_equal(result, expected)
+
+        # Series with index and dictionary with no index
+        expected = SparseSeries(series)
+
+        result = SparseSeries(constructor_dict)
+        tm.assert_sp_series_equal(result, expected)
+
     def test_constructor_dtype(self):
         arr = SparseSeries([np.nan, 1, 2, np.nan])
         assert arr.dtype == np.float64