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GeezerVison is showing github.com — TYP,BLD: Fix backend_pdf stub errors and install it by maaz7409 · Pull Request #32586 · matplotlib/matplotlib

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maaz7409 commented Nov 9, 2026

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PR summary

This PR is follow-up to #32481, which installed registry.pyi and left
backend_pdf.pyi out because its errors would reject valid code.
It fixes those errors and adds backend_pdf.pyi to typing_sources.

Fixes

Valid code rejected by the stub	Fix
`pdf.savefig(fig, dpi=300)`	`kwargs: dict[str, Any]` → `kwargs: Any`
`fig.savefig(pdf)`, `plt.savefig(pdf)`	accept `PdfPages` as `fname`, as the `Figure.savefig` docstring says
`PdfPages(f, metadata={"CreationDate": None})` (documented) and `PdfPages(f, metadata=md)` with `md: dict[str, str]`	type `metadata` as `Mapping[str, str \| datetime \| Name \| None]`; `infodict()` still returns a `dict`
`gc.paint(fill_rule=...)`, `Op.paint_path(..., fill_rule=...)`	add `fill_rule` (from #32253)
`Op.paint_path(...).pdfRepr()`	return type `bytes` → `Op`, as at runtime
`Op.fill_evenodd`, `Op.fill_evenodd_stroke`	add the members (from #32253)
`from matplotlib.backends.backend_pdf import FigureManagerPdf`	add the alias

I checked with mypy and stubtest (16 → 1 mypy errors on valid usage, 23 → 18 stubtest differences, none from the changed items)

Also tests : ruff, CI's mypy run, test_backend_pdf.py and test_pyplot_up_to_date pass.

AI Disclosure

Claude Code ( Claude Opus 5.5 (high) ) assisted me in writing the fix.

PR quality check

Use an expressive title, e.g. "Fix title font property precedence"
[N/A] New and changed code is tested (stub-only change)
[N/A] Plotting related features are demonstrated in an example
[N/A] New features and API changes have release notes
[N/A] Documentation complies with general and docstring guidelines

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          TYP: Fix errors in the backend_pdf stub

f705350

github-actions Bot added topic: pyplot API topic: figures and subfigures labels

Nov 9, 2026

timhoffm reviewed

Nov 9, 2026

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lib/matplotlib/figure.pyi Outdated

		def savefig(
		self,
		fname: str \| os.PathLike \| IO,
		fname: str \| os.PathLike \| IO \| PdfPages,

timhoffm Nov 9, 2026

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It's more complicated than that. fname is passed on to self.canvas.print_figure, and FigureCanvasBase.print_figure does not accept PdfPages either. Mypy doesn't flag this only because, with figure.pyi present, the implementation of Figure.savefig is never type-checked against the stubs.

The type system can't reasonably express the current situation, where the types savefig accepts depend on the runtime type of another object (figure.canvas). Adding PdfPages to FigureCanvasBase.print_figure would mean adding it to all canvas subclasses as well: too permissive, cumbersome, and ultimately impractical for third-party backends.

T.b.h. I just wouldn't bother with the type imperfection.

The backend_pdf.pyi changes themselves seem ok.

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maaz7409 Nov 10, 2026

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Ok, so do i drop both commits : fname changes to this figure.pyi as well as pyplot.py ?

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          BLD: Install the type stub for backends.backend_pdf

0fa049d

maaz7409 force-pushed the typ-fix-install-backend-pdf-stub branch from b19f8ec to 0fa049d Compare

November 10, 2026 10:08

github-actions Bot removed topic: pyplot API topic: figures and subfigures labels

Nov 10, 2026

timhoffm approved these changes

Nov 10, 2026

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