How can I speed up Dash and Plotly imports?

Question

For me, the dash and plotly.express packages are taking an excessive amount of time to import. I used this code to check the import times:

print("Start")

import time

t0 = time.time()
import dash
print(f"Time to load dash: {time.time()-t0}")

t0 = time.time()
import plotly
print(f"Time to load plotly: {time.time()-t0}")

t0 = time.time()
import plotly.express as px
print(f"Time to load plotly.express: {time.time()-t0}")

t0 = time.time()
from dash import dcc
print(f"Time to load dcc: {time.time()-t0}")

t0 = time.time()
from dash import html
print(f"Time to load html: {time.time()-t0}")

t0 = time.time()
from dash.dependencies import State, Input, Output
print(f"Time for dependencies: {time.time()-t0}")

As an output, I got that dash took ~55 seconds, plotly took ~0.6 seconds, plotly.express took ~100 seconds, and everything else took 0 seconds.

I am using a Conda virtual environment for this, with these package versions:

• python: 3.9.10
• dash: 2.2.0
• plotly: 5.6.0

There are some other packages in the venv too, mostly dependents of those packages and pandas.

The virtual environment and the code I want to run are in different directories in the same drive. I used pip and conda channels provided by my workplace to download these packages, if that makes a difference.

What could be causing this?