feat(pandas): support memtable in pandas backend

Closes #5467

Author: anjakefala

ibis/backends/pandas/execution/generic.py

@@ -1442,6 +1442,11 @@ def execute_zero_if_null_series(op, data, **kwargs):
     return data.replace({np.nan: zero, None: zero, pd.NA: zero})
 
 
+@execute_node.register(ops.InMemoryTable)
+def execute_in_memory_table(op, **kwargs):
+    return op.data.to_frame()
+
+
 @execute_node.register(
     ops.ZeroIfNull,
     (type(None), type(pd.NA), numbers.Real, np.integer, np.floating),

ibis/backends/tests/test_generic.py

@@ -916,7 +916,7 @@ def test_literal_na(con, dtype):
 
 
 @pytest.mark.notimpl(["datafusion"], raises=com.OperationNotDefinedError)
-@pytest.mark.notimpl(["dask", "pandas"], raises=com.UnboundExpressionError)
+@pytest.mark.notimpl(["dask"], raises=com.UnboundExpressionError)
 def test_memtable_bool_column(backend, con, monkeypatch):
     monkeypatch.setattr(ibis.options, "default_backend", con)
 
@@ -925,7 +925,7 @@ def test_memtable_bool_column(backend, con, monkeypatch):
 
 
 @pytest.mark.notimpl(["datafusion"], raises=com.OperationNotDefinedError)
-@pytest.mark.notimpl(["dask", "pandas"], raises=com.UnboundExpressionError)
+@pytest.mark.notimpl(["dask"], raises=com.UnboundExpressionError)
 @pytest.mark.broken(
     ["druid"],
     raises=AssertionError,