Hm. I just looked how this can be accomplished in PyGMT and at least for me, @! works to combine any letter with a v on top (\237):
import pygmt
size = 5
fig = pygmt.Figure()
fig.basemap(
region=[-size, size, -size, size],
projection=f"X{size}c",
frame="x+l@!s\\237 @!r\\237 @!c\\237", # two \ needed in PyGMT / Python
)
fig.text(position="MC", text="@!s\\237 @!r\\237 @!c\\237")
fig.colorbar(cmap="batlow", position="jTC", frame="x+l@!s\\237 @!r\\237 @!c\\237")
fig.show()
