Apply copy-on-write context only when pandas < 3.0

Author: has2k1

doc/changelog.qmd

@@ -2,13 +2,22 @@
 title: Changelog
 ---
 
-## v0.15.1
+## v0.15.3
+(2025-01-28)
+
+### Enhancements
+
+- Removed warnings about copy-on-write for pandas >= 3.0.0
+
+## v0.15.2
 (2025-12-12)
 
 ### Bug Fixes
-
 - Fixed random failures for when using plotnine in quarto == 1.8.26. {{< issue 1017 >}}
 
+## v0.15.1
+(2025-09-30)
+
 ### New
 
 - Added [](:class:`~plotnine.scale_stroke_identity`) which was conspicuously missing!

plotnine/_utils/context.py

@@ -4,13 +4,16 @@
 from typing import TYPE_CHECKING
 
 import pandas as pd
+from packaging.version import Version
 
 if TYPE_CHECKING:
     from typing_extensions import Self
 
     from plotnine import ggplot
     from plotnine.composition import Compose
 
+PANDAS_LT_3 = Version(pd.__version__) < Version("3.0")
+
 
 def reopen(fig):
     """
@@ -55,20 +58,20 @@ def __init__(self, plot: ggplot, show: bool = False):
 
         # Contexts
         self.rc_context = mpl.rc_context(plot.theme.rcParams)
-        # TODO: Remove this context when copy-on-write is permanent, i.e.
-        # pandas >= 3.0
-        self.pd_option_context = pd.option_context(
-            "mode.copy_on_write",
-            True,
-        )
+        if PANDAS_LT_3:
+            self.pd_option_context = pd.option_context(
+                "mode.copy_on_write",
+                True,
+            )
 
     def __enter__(self) -> Self:
         """
         Enclose in matplolib & pandas environments
         """
 
         self.rc_context.__enter__()
-        self.pd_option_context.__enter__()
+        if PANDAS_LT_3:
+            self.pd_option_context.__enter__()
 
         return self
 
@@ -89,7 +92,8 @@ def __exit__(self, exc_type, exc_value, exc_traceback):
                 plt.close(self.plot.figure)
 
         self.rc_context.__exit__(exc_type, exc_value, exc_traceback)
-        self.pd_option_context.__exit__(exc_type, exc_value, exc_traceback)
+        if PANDAS_LT_3:
+            self.pd_option_context.__exit__(exc_type, exc_value, exc_traceback)
 
 
 @dataclass

pyproject.toml

@@ -28,7 +28,7 @@ dependencies = [
     "mizani~=0.14.0",
     "numpy>=1.23.5",
     "scipy>=1.8.0",
-    "statsmodels>=0.14.5",
+    "statsmodels>=0.14.6",
 ]
 requires-python = ">=3.10"
 

tests/baseline_images/test_scale_internals/missing_data_discrete_position_scale.png

@@ -633,12 +633,11 @@ def test_missing_data_discrete_scale():
 def test_missing_data_discrete_position_scale():
     data = pd.DataFrame({"a": [1, 2, 3], "b": ["a", "b", None]})
 
+    # The missing data is not removed
     p = ggplot(data, aes("a", "b")) + geom_point(
         aes(fill="b"), stroke=0, size=10
     )
-
-    with pytest.warns(PlotnineWarning):
-        assert p == "missing_data_discrete_position_scale"
+    assert p == "missing_data_discrete_position_scale"
 
 
 data = pd.DataFrame(