I don’t think you can do it automatically but you can use the Image interface to get to the expected result.
For instance you could do the following (in the example I put the round flag icons in the folder flags/png/512):
from PIL import Image
import plotly.express as px
df = px.data.gapminder().query("year==2007")
fig = px.scatter(
df,
x="lifeExp",
y="gdpPercap",
hover_name="country",
hover_data=["lifeExp", "gdpPercap", "pop"]
)
fig.update_traces(marker_color="rgba(0,0,0,0)")
maxDim = df[["lifeExp", "gdpPercap"]].max().idxmax()
maxi = df[maxDim].max()
for i, row in df.iterrows():
country = row['country'].replace(" ", "-")
fig.add_layout_image(
dict(
source=Image.open(f"flags/png/512/{country}.png"),
xref="x",
yref="y",
xanchor="center",
yanchor="middle",
x=row["lifeExp"],
y=row["gdpPercap"],
sizex=np.sqrt(row["pop"] / df["pop"].max()) * maxi * 0.2 + maxi * 0.05,
sizey=np.sqrt(row["pop"] / df["pop"].max()) * maxi * 0.2 + maxi * 0.05,
sizing="contain",
opacity=0.8,
layer="above"
)
)
fig.update_layout(height=600, width=1000, yaxis_range=[-5e3, 55e3], plot_bgcolor="#dfdfdf")
fig.show()
Which would give you the following:
