The issue is that plotly's template system has a circular import dependency:

1. plotly.graph_objs.__init__.py imports all trace types including Heatmapgl
2. During this import process, it also loads template data
3. layout/template/data/_heatmapgl.py tries toimport Heatmapgl from plotly.graph_objs
4. But plotly.graph_objs is still in the process of being imported!

This occurred when attempting to use plotly and plotly-resampler and a heatmap.

Reproduction of Error

Minimal reproduction code:

importplotly.graph_objsasgogo.Heatmapgl()# ✅ Success# But this fails:fromplotly_resamplerimportFigureResamplerfig=FigureResampler(go.Figure())# ❌ Circular import

Versions affected:

plotly==5.24.1
plotly-resampler==0.10.0

Work around

This can be worked around by forcing import order:

importplotly.graph_objs# Force full initialization firstfromplotly_resamplerimportFigureResampler# Then import resampler