Fix installation under Pyodide 314 (matplotlib 3.10)

doc/changelog.qmd

@@ -110,6 +110,14 @@ title: Changelog
   `geom="blank"`, `position="identity"` and `na_rm=False`, so all geoms and
   stats include them automatically.
 
+- plotnine now supports Matplotlib 3.10. This allows installation under
+  Pyodide. Matplotlib 3.10 and 3.11 use different text metrics, so text
+  extents, line spacing, and plot margins may differ. Use Matplotlib 3.11 or
+  later to reproduce the documentation output.
+
+- `statsmodels>=0.14.6` is now required on every platform. This replaces the
+  separate `statsmodels<=0.14.4` requirement for Pyodide.
+
 ### Bug Fixes
 
 - [](:class:`~plotnine.scale_size_datetime`) now honours its `range`

plotnine/_mpl/__init__.py

@@ -0,0 +1,8 @@
+import matplotlib as mpl
+from packaging.version import Version
+
+# Matplotlib 3.10 requires numeric line spacing and produces different text
+# extents from 3.11. Text elements use this flag to convert `normal`; the test
+# suite uses it to require Matplotlib 3.11. Remove the flag and both uses when
+# plotnine requires Matplotlib 3.11.
+MPL_LT_311 = Version(mpl.__version__) < Version("3.11")

plotnine/_mpl/axes.py

@@ -32,8 +32,8 @@ class p9Axes(Axes):
 
     name = "plotnine"
 
-    # mpl resolves every Axis operation through the per-name axis
-    # registries; the secondary axes register under their own names.
+    # Matplotlib looks up shared axes in the registry for each axis name.
+    # Secondary axes use distinct names.
     _shared_axes = {
         **Axes._shared_axes,  # pyright: ignore[reportAttributeAccessIssue]
         "sec_x": cbook.Grouper(),
@@ -59,6 +59,27 @@ def __init__(self, *args, **kwargs):
         # the spine of the side it occupies.
         self.spines[:].set_visible(False)
 
+    @property
+    def _axis_map(self) -> dict[str, XAxis | YAxis]:
+        """
+        Mapping from Matplotlib axis names to panel axes
+
+        Matplotlib uses this mapping to resolve tick and limit operations.
+        """
+        m: dict[str, XAxis | YAxis] = {"x": self.xaxis, "y": self.yaxis}
+        if self.sec_xaxis is not None:
+            m["sec_x"] = self.sec_xaxis
+        if self.sec_yaxis is not None:
+            m["sec_y"] = self.sec_yaxis
+        return m
+
+    @_axis_map.setter
+    def _axis_map(self, value: dict[str, XAxis | YAxis]):  # pyright: ignore[reportIncompatibleVariableOverride]
+        # Matplotlib 3.11 and later assign the primary axes here during panel
+        # initialisation. The getter derives that mapping from the panel, so
+        # ignore the assigned value.
+        ...
+
     def add_sec_axis(self, side: Side) -> XAxis | YAxis:
         """
         Return the secondary axis for `side`, creating it if needed
@@ -78,19 +99,17 @@ def add_sec_axis(self, side: Side) -> XAxis | YAxis:
         """
         if side in ("top", "bottom"):
             if self.sec_xaxis is None:
-                self.sec_xaxis = self._make_sec_axis(XAxis, "sec_x")
+                self.sec_xaxis = self._make_sec_axis(XAxis)
             return self.sec_xaxis
         else:
             if self.sec_yaxis is None:
-                self.sec_yaxis = self._make_sec_axis(YAxis, "sec_y")
+                self.sec_yaxis = self._make_sec_axis(YAxis)
             return self.sec_yaxis
 
-    def _make_sec_axis(self, cls: type[AxisT], name: str) -> AxisT:
+    def _make_sec_axis(self, cls: type[AxisT]) -> AxisT:
         axis = cls(self)
-        # Register the axis so mpl can resolve its name, and add it to
-        # the draw tree. Panels are never cleared after this point;
-        # Axes.clear() would detach the artist.
-        self._axis_map[name] = axis
+        # Add the axis to the draw tree. Plotnine does not clear the panel
+        # after this point because clearing it would detach the secondary axis.
         self.add_artist(axis)
         axis.set_clip_on(False)
         axis.grid(False)

plotnine/themes/elements/element_text.py

@@ -7,6 +7,8 @@
 from contextlib import suppress
 from typing import TYPE_CHECKING
 
+from plotnine._mpl import MPL_LT_311
+
 from .element_base import element_base
 from .margin import margin as Margin
 
@@ -152,6 +154,9 @@ def __init__(
         with suppress(KeyError):
             rotation = kwargs.pop("angle")
 
+        if MPL_LT_311 and linespacing == "normal":
+            linespacing = 1.2
+
         super().__init__()
         self.properties.update(**kwargs)
 

pyproject.toml

@@ -23,16 +23,12 @@ classifiers = [
     "Topic :: Scientific/Engineering :: Visualization"
 ]
 dependencies = [
-    "matplotlib>=3.11.0",
+    "matplotlib>=3.10.0",
     "pandas>=2.2.0",
     "mizani~=0.14.0",
     "numpy>=1.25.0",
     "scipy>=1.15.0",
-    # pyodide ships with statmodels==0.14.4 which is broken for later versions
-    # of numpy and pandas
-    # https://github.com/statsmodels/statsmodels/releases/tag/v0.14.6
-    "statsmodels<=0.14.4; sys_platform == 'emscripten'",
-    "statsmodels>=0.14.6; sys_platform != 'emscripten'",
+    "statsmodels>=0.14.6",
 ]
 requires-python = ">=3.11"
 
@@ -71,6 +67,8 @@ lint = [
 ]
 
 test = [
+    # The baseline images use text metrics from Matplotlib 3.11.
+    "matplotlib>=3.11.0",
     "pytest-cov>=4.0.0",
     "pytest-xdist>=3.8.0",
     "pytest-sugar>=1.1.1",

tests/conftest.py

@@ -11,6 +11,7 @@
 from matplotlib.testing.compare import compare_images
 
 from plotnine import ggplot, theme
+from plotnine._mpl import MPL_LT_311
 from plotnine.composition import (
     Beside,
     Compose,
@@ -50,6 +51,14 @@
         "test data."
     )
 
+if MPL_LT_311:
+    raise OSError(
+        "Install Matplotlib>=3.11 to run the tests. The baseline images use "
+        "Matplotlib 3.11 text metrics, which differ from those in installed "
+        f"Matplotlib {mpl.__version__}. plotnine itself supports "
+        "Matplotlib>=3.10."
+    )
+
 
 def raise_no_baseline_image(filename: str):
     raise Exception(f"Baseline image {filename} is missing")

tests/test_sec_axis.py

@@ -138,3 +138,15 @@ def test_facet_wrap_sec_axis():
         + scale_y_continuous(sec_axis=sec_axis(lambda y: y * 2, name="2x"))
     )
     assert p == "facet_wrap_sec_axis"
+
+
+def test_secondary_axis_resolves_its_name():
+    # Matplotlib resolves tick and limit operations through the panel's named
+    # axes. Preserve distinct names for the primary and secondary axes.
+    plot = p0 + scale_y_continuous(sec_axis=dup_axis())
+    plot.draw_test()
+    ax = plot.axs[0]
+
+    assert ax._axis_map["sec_y"] is ax.sec_yaxis
+    assert ax.sec_yaxis._get_axis_name() == "sec_y"
+    assert ax._axis_map["y"] is ax.yaxis

tests/test_theme.py

@@ -345,3 +345,18 @@ def test_blank_all_text_draws():
     # not crash when computing the tick-label padding. (Regression)
     p = ggplot() + lims(x=(0, 100), y=(0, 100)) + theme(text=element_blank())
     p.draw_test()  # pyright: ignore  # must not raise
+
+
+def test_element_text_linespacing_normal():
+    # Matplotlib 3.10 uses `1.2` for the `normal` line spacing that
+    # Matplotlib 3.11 accepts by name.
+    from plotnine._mpl import MPL_LT_311
+
+    expected = 1.2 if MPL_LT_311 else "normal"
+    assert (
+        element_text(linespacing="normal").properties["linespacing"]
+        == expected
+    )
+    assert (
+        element_text(lineheight="normal").properties["linespacing"] == expected
+    )