From b3d961998b6cf6a6fcff5e1405e1b37b144dd5f6 Mon Sep 17 00:00:00 2001
From: Phillip Cloud <417981+cpcloud@users.noreply.github.com>
Date: Thu, 8 Jun 2023 11:09:21 -0400
Subject: [PATCH] feat(api): add `__dataframe__` implementation

---
 ibis/backends/tests/test_export.py | 16 ++++++++++++++++
 ibis/expr/types/relations.py       |  3 +++
 2 files changed, 19 insertions(+)

diff --git a/ibis/backends/tests/test_export.py b/ibis/backends/tests/test_export.py
index 630d1bd061da..6f5a94db81e7 100644
--- a/ibis/backends/tests/test_export.py
+++ b/ibis/backends/tests/test_export.py
@@ -396,3 +396,19 @@ def test_arrow_timestamp_with_time_zone(alltypes):
 
     (batch,) = t.to_pyarrow_batches()
     assert batch.schema.types == expected
+
+
+@pytest.mark.notimpl(["dask", "druid"])
+@pytest.mark.notimpl(
+    ["mysql"],
+    raises=pa.ArrowInvalid,
+    reason="attempted conversion from decimal to double",
+)
+@pytest.mark.notimpl(
+    ["impala"], raises=AttributeError, reason="missing `fetchmany` on the cursor"
+)
+def test_dataframe_protocol(alltypes):
+    pytest.importorskip("pyarrow", minversion="12")
+    output = alltypes.__dataframe__()
+    assert list(output.column_names()) == alltypes.columns
+    assert alltypes.count().execute() == output.num_rows()
diff --git a/ibis/expr/types/relations.py b/ibis/expr/types/relations.py
index 4176d7cec355..64439f598f66 100644
--- a/ibis/expr/types/relations.py
+++ b/ibis/expr/types/relations.py
@@ -109,6 +109,9 @@ class Table(Expr, _FixedTextJupyterMixin):
     def __array__(self, dtype=None):
         return self.execute().__array__(dtype)
 
+    def __dataframe__(self):
+        return self.to_pyarrow().__dataframe__()
+
     def as_table(self) -> Table:
         """Promote the expression to a table.