fix .hvplot for ibis

hvplot/converter.py

@@ -851,7 +851,7 @@ def _process_data(self, kind, data, x, y, by, groupby, row, col,
                                  'e.g. a NumPy array or xarray Dataset, '
                                  'found %s type' % (kind, type(self.data).__name__))
 
-            if hasattr(data, 'columns') and data.columns.name and not group_label:
+            if hasattr(data, 'columns') and hasattr(data.columns, 'name') and data.columns.name and not group_label:
                 group_label = data.columns.name
             elif not group_label:
                 group_label = 'Variable'

hvplot/ibis.py

@@ -4,8 +4,8 @@ def patch(name='hvplot', extension='bokeh', logo=False):
     try:
         import ibis
     except:
-        raise ImportError('Could not patch plotting API onto dask. '
-                          'Dask could not be imported.')
+        raise ImportError('Could not patch plotting API onto ibis. '
+                          'Ibis could not be imported.')
     _patch_plot = lambda self: hvPlotTabular(self)
     _patch_plot.__doc__ = hvPlotTabular.__call__.__doc__
     patch_property = property(_patch_plot)

hvplot/tests/testibis.py

@@ -0,0 +1,22 @@
+"""Ibis works with hvplot"""
+import pytest
+
+try:
+    import ibis
+    import hvplot.ibis # noqa
+    import pandas as pd
+except:
+    pytest.skip(allow_module_level=True)
+
+
+@pytest.fixture
+def table():
+    df = pd.DataFrame({
+        "x": [pd.Timestamp("2022-01-01"), pd.Timestamp("2022-01-02")], "y": [1,2]
+    })
+    con = ibis.pandas.connect({"df": df})
+    return con.table("df")
+
+def test_can_hvplot(table):
+    """hvplot works with Ibis"""
+    table.hvplot(x="x", y="y")