fix: Fix error loading local dataframes into bigquery (#1165)

Author: TrevorBergeron

bigframes/session/loader.py

@@ -158,10 +158,12 @@ def read_pandas_load_job(
             ordering_col = f"rowid_{suffix}"
             suffix += 1
 
+        # Maybe should just convert to pyarrow or parquet?
         pandas_dataframe_copy = pandas_dataframe.copy()
         pandas_dataframe_copy.index.names = new_idx_ids
         pandas_dataframe_copy.columns = pandas.Index(new_col_ids)
         pandas_dataframe_copy[ordering_col] = np.arange(pandas_dataframe_copy.shape[0])
+        pandas_dataframe_copy = pandas_dataframe_copy.reset_index(drop=False)
 
         job_config = bigquery.LoadJobConfig()
         # Specify the datetime dtypes, which is auto-detected as timestamp types.

tests/system/small/test_dataframe.py

@@ -99,6 +99,20 @@ def test_df_construct_pandas_load_job(scalars_dfs_maybe_ordered):
     assert_dfs_equivalent(pd_result, bf_result)
 
 
+def test_df_construct_structs(session):
+    pd_frame = pd.Series(
+        [
+            {"version": 1, "project": "pandas"},
+            {"version": 2, "project": "pandas"},
+            {"version": 1, "project": "numpy"},
+        ]
+    ).to_frame()
+    bf_series = session.read_pandas(pd_frame)
+    pd.testing.assert_frame_equal(
+        bf_series.to_pandas(), pd_frame, check_index_type=False, check_dtype=False
+    )
+
+
 def test_df_construct_pandas_set_dtype(scalars_dfs):
     columns = [
         "int64_too",