Add fix: deduplicate columns

dylanhmorris · dylanhmorris · commit 56e3f65a8ba0 · 2025-08-26T14:25:47.000-04:00
diff --git a/xarray/core/dataset.py b/xarray/core/dataset.py
@@ -7234,6 +7234,14 @@ def _to_dataframe(self, ordered_dims: Mapping[Any, int]):
                 0
             ]
             broadcasted_df = broadcasted_df.join(extension_array_df)
+        # remove columns also represented as levels of the MultiIndex. This is necessary
+        # because otherwise MultiIndex levels may otherwise be duplicated as columns and
+        # is safe because xarray forbids clashes between Data variable names and coordinate names,
+        # so any named multi-index levels that clash with a coordinate-derived column
+        # must be derived from that same array.
+        columns_in_order = [
+            c for c in columns_in_order if c not in broadcasted_df.index.names
+        ]
         return broadcasted_df[columns_in_order]
 
     def to_dataframe(self, dim_order: Sequence[Hashable] | None = None) -> pd.DataFrame:

Original file line number	Diff line number	Diff line change
`@@ -7234,6 +7234,14 @@ def _to_dataframe(self, ordered_dims: Mapping[Any, int]):`
`7234`	`7234`	`0`
`7235`	`7235`	`]`
`7236`	`7236`	`broadcasted_df = broadcasted_df.join(extension_array_df)`
	`7237`	`+ # remove columns also represented as levels of the MultiIndex. This is necessary`
	`7238`	`+ # because otherwise MultiIndex levels may otherwise be duplicated as columns and`
	`7239`	`+ # is safe because xarray forbids clashes between Data variable names and coordinate names,`
	`7240`	`+ # so any named multi-index levels that clash with a coordinate-derived column`
	`7241`	`+ # must be derived from that same array.`
	`7242`	`+ columns_in_order = [`
	`7243`	`+ c for c in columns_in_order if c not in broadcasted_df.index.names`
	`7244`	`+ ]`
`7237`	`7245`	`return broadcasted_df[columns_in_order]`
`7238`	`7246`
`7239`	`7247`	`def to_dataframe(self, dim_order: Sequence[Hashable] \| None = None) -> pd.DataFrame:`