Feature/#755 - Open append() method on datanodes

src/taipy/core/data/parquet.py

@@ -227,6 +227,9 @@ def _read_as_pandas_dataframe(self, read_kwargs: Dict) -> pd.DataFrame:
     def _read_as_modin_dataframe(self, read_kwargs: Dict) -> modin_pd.DataFrame:
         return modin_pd.read_parquet(self._path, **read_kwargs)
 
+    def _append(self, data: Any):
+        self.write_with_kwargs(data, engine="fastparquet", append=True)
+
     def _write(self, data: Any):
         self.write_with_kwargs(data)
 

tests/core/data/test_parquet_data_node.py

@@ -300,6 +300,50 @@ def test_get_system_folder_modified_date_instead_of_last_edit_date(self, tmpdir_
 
         os.unlink(temp_file_path)
 
+    @pytest.mark.parametrize(
+        "content",
+        [
+            ([{"a": 11, "b": 22, "c": 33}, {"a": 44, "b": 55, "c": 66}]),
+            (pd.DataFrame([{"a": 11, "b": 22, "c": 33}, {"a": 44, "b": 55, "c": 66}])),
+        ],
+    )
+    def test_append_pandas(self, parquet_file_path, default_data_frame, content):
+        # !!! append data only works with `fastparquet`
+        if not util.find_spec("fastparquet"):
+            pass
+
+        dn = ParquetDataNode("foo", Scope.SCENARIO, properties={"path": parquet_file_path})
+        assert_frame_equal(dn.read(), default_data_frame)
+
+        dn.append(content)
+        assert_frame_equal(
+            dn.read(),
+            pd.concat([default_data_frame, pd.DataFrame(content, columns=["a", "b", "c"])]).reset_index(drop=True),
+        )
+
+    @pytest.mark.parametrize(
+        "content",
+        [
+            ([{"a": 11, "b": 22, "c": 33}, {"a": 44, "b": 55, "c": 66}]),
+            (pd.DataFrame([{"a": 11, "b": 22, "c": 33}, {"a": 44, "b": 55, "c": 66}])),
+        ],
+    )
+    def test_append_modin(self, parquet_file_path, default_data_frame, content):
+        # !!! append data only works with `fastparquet`
+        if not util.find_spec("fastparquet"):
+            pass
+
+        dn = ParquetDataNode("foo", Scope.SCENARIO, properties={"path": parquet_file_path, "exposed_type": "modin"})
+        df_equals(dn.read(), modin_pd.DataFrame(default_data_frame))
+
+        dn.append(content)
+        df_equals(
+            dn.read(),
+            modin_pd.concat([default_data_frame, pd.DataFrame(content, columns=["a", "b", "c"])]).reset_index(
+                drop=True
+            ),
+        )
+
     @pytest.mark.parametrize(
         "data",
         [