You can draw both arcs of circle or ellipse, and filled circle or ellipse calling a function that defines the corresponding svg paths:

```
import numpy as np
import plotly.graph_objects as go
def ellipse_arc(x_center=0, y_center=0, a=1, b =1, start_angle=0, end_angle=2*np.pi, N=100, closed= False):
t = np.linspace(start_angle, end_angle, N)
x = x_center + a*np.cos(t)
y = y_center + b*np.sin(t)
path = f'M {x[0]}, {y[0]}'
for k in range(1, len(t)):
path += f'L{x[k]}, {y[k]}'
if closed:
path += ' Z'
return path
fig = go.Figure()
# Create a minimal trace
fig.add_trace(go.Scatter(
x=[0],
y=[0.2],
marker_size=0.1
));
fig.update_layout(width =600, height=400,
xaxis_range=[-5.2, 5.2],
yaxis_range=[-3.2, 3.2],
shapes=[
dict(type="path",
path= ellipse_arc(a=5, b=3, start_angle=-np.pi/6, end_angle=3*np.pi/2, N=60),
line_color="RoyalBlue"),
dict(type="path",
path = ellipse_arc(x_center=2, a= 0.5, b= 1.5, closed=True),
fillcolor="LightPink",
line_color="Crimson")
]
);
fig.show()
```

If a=b youโll get an arc of circle (if layout.width=layout.height), otherwise an arc of ellipse.