Merge pull request #345 from iiasa/read_excel-correction

Correct error in io.s_read_excel for items on multiple sheets

RELEASE_NOTES.rst

@@ -4,20 +4,15 @@ Next release
 All changes
 -----------
 
+- :pull:`345`: Fix a bug in :meth:`.read_excel` when parameter data is spread across multiple sheets.
 - :pull:`363`: Expand documentation and revise installation instructions.
 - :pull:`362`: Raise Python exceptions from :class:`.JDBCBackend`.
 - :pull:`354`: Add :meth:`Scenario.items`, :func:`.utils.diff`, and allow using filters in CLI command ``ixmp export``.
-- :pull:`353`: Add meta functionality.
-
-  - :meth:`.Platform.add_model_name` using :meth:`.Backend.add_model_name`
-  - :meth:`.Platform.add_scenario_name` using :meth:`.Backend.add_scenario_name`
-  - :meth:`.Platform.get_model_names` using :meth:`.Backend.get_model_names`
-  - :meth:`.Platform.get_scenario_names` using :meth:`.Backend.get_scenario_names`
-  - :meth:`.Platform.get_meta` using :meth:`.Backend.get_meta`
-  - :meth:`.Platform.set_meta` using :meth:`.Backend.set_meta`
-  - :meth:`.Platform.remove_meta` using :meth:`.Backend.remove_meta`
-  - :meth:`.Scenario.remove_meta` using :meth:`.Backend.remove_meta`
-  - deprecate :meth:`.Scenario.delete_meta`
+- :pull:`353`: Add functionality for storing ‘meta’ (annotations of model names, scenario names, versions, and some combinations thereof).
+
+  - Add :meth:`.Backend.add_model_name`, :meth:`~.Backend.add_scenario_name`, :meth:`~.Backend.get_model_names`, :meth:`~.Backend.get_scenario_names`, :meth:`~.Backend.get_meta`, :meth:`~.Backend.set_meta`, :meth:`~.Backend.remove_meta`.
+  - Allow these to be called from :class:`.Platform` instances.
+  - Remove :meth:`.Scenario.delete_meta`.
 
 - :pull:`349`: Avoid modifying indexers dictionary in :meth:`.AttrSeries.sel`.
 - :pull:`343`: Add region/unit parameters to :meth:`.Platform.export_timeseries_data`.

ixmp/backend/io.py

@@ -203,7 +203,7 @@ def parse_item_sheets(name):
             dfs.append(xf.parse(x))
 
         # Concatenate once and return
-        return pd.concat(dfs, axis=1)
+        return pd.concat(dfs, axis=0)
 
     # Add sets in two passes:
     # 1. Index sets, required to initialize other sets.

ixmp/tests/backend/test_io.py

@@ -0,0 +1,27 @@
+import ixmp
+from ixmp.testing import add_random_model_data, models
+
+
+def test_read_excel_big(test_mp, tmp_path):
+    """Excel files with model items split across sheets can be read.
+
+    https://github.com/iiasa/ixmp/pull/345.
+    """
+    tmp_path /= 'output.xlsx'
+
+    # Write a 25-element parameter with max_row=10 → split across 3 sheets
+    scen = ixmp.Scenario(test_mp, **models['dantzig'], version="new")
+    add_random_model_data(scen, 25)
+    scen.to_excel(tmp_path, items=ixmp.ItemType.MODEL, max_row=10)
+
+    # Initialize target scenario for reading
+    scen_empty = ixmp.Scenario(test_mp, "foo", "bar", version="new")
+    scen_empty.init_set("random_set")
+    scen_empty.init_par(
+        "random_par", scen.idx_sets("random_par"), scen.idx_names("random_par")
+    )
+
+    # File can be read
+    scen_empty.read_excel(tmp_path)
+
+    assert len(scen_empty.par("random_par")) == 25