fix casting with empty dataframes

fennel/CHANGELOG.md

@@ -1,5 +1,8 @@
 # Changelog
 
+## [1.5.62] - 2024-12-16
+- Fix casting for empty dataframes.
+
 ## [1.5.61] - 2024-12-12
 - Add appropriate warnings for aggregations on top of keyed datasets.
 

fennel/testing/executor.py

@@ -334,7 +334,7 @@ def join_aggregated_dataset(
 
             for col in key_dfs.columns:
                 # If any of the columns is a dictionary, convert it to a frozen dict
-                if key_dfs[col].apply(lambda x: isinstance(x, dict)).any():
+                if any([isinstance(x, dict) for x in key_dfs[col].tolist()]):
                     key_dfs[col] = key_dfs[col].apply(lambda x: frozendict(x))
 
             # Find the values for all columns as of the timestamp in key_dfs

fennel/testing/test_utils.py

@@ -381,7 +381,9 @@ def add_deletes(
             last_index_for_key[key] = i
 
     # Add the delete timestamp as a hidden column to the dataframe
-    sorted_df[FENNEL_DELETE_TIMESTAMP] = delete_timestamps
+    sorted_df[FENNEL_DELETE_TIMESTAMP] = pd.Series(
+        delete_timestamps, dtype=pd.ArrowDtype(pa.timestamp("ns", "UTC"))
+    )
 
     if len(rows_to_delete) > 0:
         # Drop the rows that are marked for deletion

pyproject.toml

@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "fennel-ai"
-version = "1.5.61"
+version = "1.5.62"
 description = "The modern realtime feature engineering platform"
 authors = ["Fennel AI <[email protected]>"]
 packages = [{ include = "fennel" }]