TST: Skip a test for pandas < 3.

Author: has2k1

tests/test_scale_internals.py

@@ -5,6 +5,7 @@
 import numpy.testing as npt
 import pandas as pd
 import pytest
+from packaging.version import Version
 
 import plotnine as p9
 from plotnine import (
@@ -57,6 +58,8 @@
 )
 from plotnine.scales.scales import make_scale
 
+PANDAS_LT_3 = Version(pd.__version__) < Version("3.0")
+
 
 # test palettes
 def test_discrete_color_palettes():
@@ -630,6 +633,7 @@ def test_missing_data_discrete_scale():
     assert p == "missing_data_discrete_scale"
 
 
+@pytest.mark.skipif(PANDAS_LT_3, reason="Fails on pandas<3")
 def test_missing_data_discrete_position_scale():
     data = pd.DataFrame({"a": [1, 2, 3], "b": ["a", "b", None]})