docs: improve prefix default rendering (#4069)

Author: flying-sheep

hatch.toml

@@ -38,7 +38,7 @@ overrides.matrix.deps.python = [
 overrides.matrix.deps.extra-dependencies = [
     { if = [ "stable" ], value = "scipy>=1.17" },
     { if = [ "pre" ], value = "anndata @ git+https://github.com/scverse/anndata.git" },
-    { if = [ "pre" ], value = "pandas>=3rc0" },
+    { if = [ "pre" ], value = "pandas>=3" },
 ]
 overrides.matrix.deps.dependency-groups = [
     { if = [ "stable", "pre", "low-vers" ], value = "test" },

src/scanpy/_settings/__init__.py

@@ -106,7 +106,7 @@ def preset(cls) -> Preset:
     @preset.setter
     def preset(cls, preset: Preset | str) -> None:
         new_preset = Preset(preset)
-        new_preset.check_deps()
+        new_preset.check()
         cls._preset = new_preset
 
     @property

src/scanpy/_settings/presets.py

@@ -6,11 +6,11 @@
 from contextlib import contextmanager
 from dataclasses import dataclass
 from functools import cached_property, partial, wraps
-from importlib.metadata import packages_distributions, requires
-from importlib.util import find_spec
+from importlib.metadata import distributions, requires
 from typing import TYPE_CHECKING, Literal, NamedTuple
 
 from packaging.requirements import Requirement
+from packaging.utils import canonicalize_name
 
 from .._utils._doctests import doctest_needs
 
@@ -51,10 +51,22 @@ def __repr__(self) -> str:
             return self.repr or "default"
         import scanpy as sc
 
+        value = self._get_value(sc.settings.preset)
+        suffix = (
+            " – changes in 2.0"
+            if sc.settings.preset is Preset.ScanpyV1
+            and value != self._get_value(Preset.ScanpyV2Preview)
+            else ""
+        )
+        return f"{value!r} (sc.settings.preset={str(sc.settings.preset)!r}{suffix})"
+
+    def _get_value(self, preset: Preset) -> object:
+        if not self.preset:
+            msg = "preset is not set"
+            raise AssertionError(msg)
         func, param = self.preset
-        params = getattr(sc.settings.preset, func)
-        value = getattr(params, param)
-        return f"{value!r} ({sc.settings.preset=} – changes in 2.0)"
+        params = getattr(preset, func)
+        return getattr(params, param)
 
 
 class HVGPreset(NamedTuple):
@@ -225,28 +237,32 @@ def override(self, preset: Preset) -> Generator[Preset, None, None]:
         finally:
             settings.preset = self
 
-    def check_deps(self) -> None:
-
+    def check(self) -> None:
+        """Check if requirements for preset are met."""
         match self:
             case self.ScanpyV1:
                 return
             case self.ScanpyV2Preview:
-                dists = {d: m for m, ds in packages_distributions().items() for d in ds}
-                missing = [
-                    r.name
-                    for r in map(Requirement, requires("scanpy"))
-                    if r.marker
-                    and r.marker.evaluate({"extra": "scanpy2"})
-                    and find_spec(dists.get(r.name, r.name.replace("-", "_"))) is None
-                ]
-                if missing:
-                    missing_str = ", ".join(f"‘{m}’" for m in missing)
-                    msg = (
-                        f"Setting preset to {Preset.ScanpyV2Preview!r} requires optional "
-                        f"dependencies that are not installed: {missing_str}. "
-                        "Install them with: pip install `scanpy[scanpy2]`"
-                    )
-                    raise ImportError(msg)
+                if not (missing := _missing_scanpy2_deps()):
+                    return
+                missing_str = ", ".join(f"‘{m.name}’" for m in missing)
+                msg = (
+                    f"Setting preset to {Preset.ScanpyV2Preview!r} requires optional "
+                    f"dependencies that are not installed: {missing_str}. "
+                    "Install them with: pip install `scanpy[scanpy2]`"
+                )
+                raise ImportError(msg)
+
+
+def _missing_scanpy2_deps() -> list[Requirement]:
+    dist_names = {canonicalize_name(d.name) for d in distributions()}
+    return [
+        r
+        for r in map(Requirement, requires("scanpy") or ())
+        if r.marker
+        and r.marker.evaluate({"extra": "scanpy2"}, "requirement")
+        and canonicalize_name(r.name) not in dist_names
+    ]
 
 
 for postprocess in preset_postprocessors:

tests/test_settings.py

@@ -1,12 +1,9 @@
 from __future__ import annotations
 
-from importlib.metadata import packages_distributions, requires
-from importlib.util import find_spec
-
 import pytest
-from packaging.requirements import Requirement
 
 import scanpy as sc
+from scanpy._settings.presets import _missing_scanpy2_deps
 
 
 # TODO: reset everything
@@ -24,20 +21,11 @@ def test_set_figure_params_warns() -> None:
 
 
 def test_preset_scanpy_v2_preview_checks_deps() -> None:
-    dists = {d: m for m, ds in packages_distributions().items() for d in ds}
-    scanpy2_deps_missing = any(
-        r.name
-        for r in map(Requirement, requires("scanpy"))
-        if r.marker
-        and r.marker.evaluate({"extra": "scanpy2"})
-        and find_spec(dists.get(r.name, r.name.replace("-", "_"))) is None
-    )
-
-    if scanpy2_deps_missing:
+    if _missing_scanpy2_deps():
         with pytest.raises(ImportError, match=r"scanpy\[scanpy2\]"):
             sc.settings.preset = sc.Preset.ScanpyV2Preview
     else:
         sc.settings.preset = sc.Preset.ScanpyV2Preview
         assert sc.settings.preset is sc.Preset.ScanpyV2Preview
         sc.settings.preset = sc.Preset.ScanpyV1
-    assert sc.settings.preset == sc.Preset.ScanpyV1
+    assert sc.settings.preset is sc.Preset.ScanpyV1