Add append parameter

Author: datapythonista

pandas/core/frame.py

@@ -3554,6 +3554,7 @@ def to_iceberg(
         *,
         catalog_properties: dict[str, Any] | None = None,
         location: str | None = None,
+        append: bool = False,
         snapshot_properties: dict[str, str] | None = None,
     ) -> None:
         """
@@ -3575,6 +3576,8 @@ def to_iceberg(
             The properties that are used next to the catalog configuration.
         location : str, optional
             Location for the table.
+        append : bool, default False
+            If ``True``, append data to the table, instead of replacing the content.
         snapshot_properties : dict of {str: str}, optional
             Custom properties to be added to the snapshot summary
 
@@ -3596,6 +3599,7 @@ def to_iceberg(
             catalog_name,
             catalog_properties=catalog_properties,
             location=location,
+            append=append,
             snapshot_properties=snapshot_properties,
         )
 

pandas/io/iceberg.py

@@ -102,6 +102,7 @@ def to_iceberg(
     *,
     catalog_properties: dict[str, Any] | None = None,
     location: str | None = None,
+    append: bool = False,
     snapshot_properties: dict[str, str] | None = None,
 ) -> None:
     """
@@ -119,6 +120,8 @@ def to_iceberg(
         The properties that are used next to the catalog configuration.
     location : str, optional
         Location for the table.
+    append : bool, default False
+        If ``True``, append data to the table, instead of replacing the content.
     snapshot_properties : dict of {str: str}, optional
         Custom properties to be added to the snapshot summary
 
@@ -142,4 +145,7 @@ def to_iceberg(
     )
     if snapshot_properties is None:
         snapshot_properties = {}
-    table.append(arrow_table, snapshot_properties=snapshot_properties)
+    if append:
+        table.append(arrow_table, snapshot_properties=snapshot_properties)
+    else:
+        table.overwrite(arrow_table, snapshot_properties=snapshot_properties)

pandas/tests/io/test_iceberg.py

@@ -178,7 +178,7 @@ def test_write_by_catalog_name(self, catalog):
         )
         tm.assert_frame_equal(result, df)
 
-    def test_write_existing_table(self, catalog):
+    def test_write_existing_table_with_append_true(self, catalog):
         original = read_iceberg(
             "ns.my_table",
             catalog_properties={"uri": catalog.uri},
@@ -194,9 +194,29 @@ def test_write_existing_table(self, catalog):
             "ns.my_table",
             catalog_properties={"uri": catalog.uri},
             location=catalog.warehouse,
+            append=True,
         )
         result = read_iceberg(
             "ns.my_table",
             catalog_properties={"uri": catalog.uri},
         )
         tm.assert_frame_equal(result, expected)
+
+    def test_write_existing_table_with_append_false(self, catalog):
+        df = pd.DataFrame(
+            {
+                "A": [1, 2, 3],
+                "B": ["foo", "foo", "foo"],
+            }
+        )
+        df.to_iceberg(
+            "ns.my_table",
+            catalog_properties={"uri": catalog.uri},
+            location=catalog.warehouse,
+            append=False,
+        )
+        result = read_iceberg(
+            "ns.my_table",
+            catalog_properties={"uri": catalog.uri},
+        )
+        tm.assert_frame_equal(result, df)