How to add white border around text?

[aborruso]

Hi,
I would like to add a thin white border to text labels

(
    ggplot(geo_df)
    + geom_map(aes(fill="costo_per_km2"), color="black", size=0.1)
    + scale_fill_cmap(cmap_name="YlOrRd")
    + geom_text(
        aes("center_lon", "center_lat", label="DEN_REGIONE"), size=8,color="black"
    )
    + labs(fill="Costo €/km²")
    + theme(
        panel_background=element_rect(fill="white"),
        panel_grid=element_blank(),
        axis_text=element_blank(),
        axis_ticks=element_blank(),
        axis_title=element_blank(),
    )
)

If I simply clone the text layers, and change the dimensions, then they turn out centered differently

    + geom_text(
        aes("center_lon", "center_lat", label="DEN_REGIONE"), size=8,color="white"
    )
    + geom_text(
        aes("center_lon", "center_lat", label="DEN_REGIONE"), size=6,color="black"
    )

This is my input file.

Thank you

[has2k1]

Use the path_effects parameter to add a stroke around the text. There is a link in the documentation to the Matplotlib tutorial.

[aborruso]

It works, thank you.

It could be a new example.

import matplotlib.patheffects as path_effects
from plotnine import *

shadow_effect = [
    path_effects.Stroke(linewidth=2, foreground="white"),  # Ombra bianca
    path_effects.Normal()  # Testo normale sopra
]

(
    ggplot(eo_df)
    + geom_map(aes(fill="costo_per_km2"), color="black", size=0.1)
    + scale_fill_cmap(cmap_name="YlOrRd")
    + geom_text(
        aes("center_lon", "center_lat", label="DEN_REGIONE"),
        size=8,
        color="black",
        path_effects=shadow_effect  # Applica direttamente i path_effects
    )
)