Bug summary

The functionsmatplotlib.rc andmatplotlib.pyplot.rc process settings given as named parameters. Named parameters can't contain hyphens; therefore, it is impossible to setfont.sans-serif so because it contains a hyphen.

It is possible to set the parameter by different means, but this seems like the main way, so I consider that it does not work a significant shortcoming. How else this parameter can be set:

• matplotlib.rcParams["font.sans-serif"] = "Fira Sans"
• matplotlib.rc("font", **{"sans-serif": "Fira Sans"})

Code for reproduction

frommatplotlibimportrcrc("font",sans-serif="Fira Sans")

Actual outcome

>>> from matplotlib import rc>>> rc("font", sans-serif="Fira Sans")  File "<python-input-1>", line 1    rc("font", sans-serif="Fira Sans")               ^^^^^^^^^^^SyntaxError: expression cannot contain assignment, perhaps you meant "=="?

Expected outcome

I think that that the parameter is namedfont.sans-serif is a mistake, and it should be named something likefont.sans_serif with an underscore. It may be too late to change that, but an alias would work.rc already has aliases likelw →linewidth,ls →linestyle,c →color. I expect that there would be an alias likesans →sans-serif so I could userc("font", sans="Fira Sans").

Additional information

No response

Operating system

No response

Matplotlib Version

3.10.1

Matplotlib Backend

No response

Python version

Python 3.13.3

Jupyter version

No response

Installation

None