Merge pull request #337 from lincc-frameworks/nest_lists_fix

fix nest_lists for non-unique index

Author: dougbrn

src/nested_pandas/nestedframe/core.py

@@ -594,9 +594,9 @@ def from_lists(cls, df, base_columns=None, list_columns=None, name="nested"):
             packed_df = pack_lists(df[list_columns])
             packed_df.name = name
 
-        # join the nested column to the base_column df
+        # concat the nested column to the base_column df
         if base_columns is not None:
-            return df[base_columns].join(packed_df)
+            return pd.concat([df[base_columns], packed_df], axis=1)
         # or just return the packed_df as a nestedframe if no base cols
         else:
             return NestedFrame(packed_df.to_frame())

tests/nested_pandas/nestedframe/test_nestedframe.py

@@ -2032,6 +2032,17 @@ def test_nest_lists():
         res = ndf.nest_lists("nested", ["c", "b"])
 
 
+def test_nestlists_nonunique_index():
+    """Test that nest_lists works with a non-unique index."""
+    nf = generate_data(5, 10)
+    nf_lists = nf["a", "b"].join(nf["nested"].nest.to_lists())
+    nf_lists.index = [0, 0, 1, 1, 2]
+    nf_repacked = nf_lists.nest_lists(["t", "flux", "band"], "nested")
+
+    nf.index = [0, 0, 1, 1, 2]
+    assert nf_repacked.equals(nf)
+
+
 def test_delitem_base_and_nested():
     """Test that __delitem__ works for both base and nested columns."""
     base = NestedFrame(data={"a": [1, 2, 3], "b": [2, 4, 6]}, index=[0, 1, 2])