A new project named PyScript, built on PyIodide, runs Python in the browser. It can actually run many of the most important scientific packages such as matplotlib, numpy, scipy, etc., and do graphics with Bokeh and others. This might be an alternative route to Leo in a browser.
I tried an example from a PyScript "Getting Started" tutorial, one that uses matplotlib to plot some random numbers. I copied the code below verbatim into a Leo node, opened viewrendered3, and the plot rendered in VR3. There was some delay while all the imported code got compiled to WebAssembly, downloaded, and initialized.
<html>
<head>
<link rel="stylesheet" href="https://pyscript.net/latest/pyscript.css" />
<script defer src="https://pyscript.net/latest/pyscript.js"></script>
</head>
<body>
<h1>Let's plot random numbers</h1>
<div id="plot"></div>
<py-config type="json">
{
"packages": ["numpy", "matplotlib"]
}
</py-config>
<py-script output="plot">
import matplotlib.pyplot as plt
import numpy as np
x = np.random.randn(1000)
y = np.random.randn(1000)
fig, ax = plt.subplots()
ax.scatter(x, y)
fig
</py-script>
</body>
</html>