I tried using the set_options method as boludo00 demonstrated. This works fine.

However when I read the edges and nodes from a DOT file the options I set afterwards with set_options have no effect.

What you can do to replicate this:

import pyvis
graph = pyvis.network.Network()
graph.from_DOT("./example_dotfile.dot")
graph.set_options("""
var options = {
    "physics": {
        "enabled": false,
        "stabilization": 10,
        "barnesHut": {
            "springLength": 200
        }
    }
}
""")
graph.show("test.html")

Here is an example DOT file for testing:

digraph {
    a [label=12];
    b [label=7];
    c [label=3];
    a -> b[label="solid edge"];                     
    a -> b [label="dashed edge"]; 
    a -> c [label="dashed edge"]; 
    a -> c [label="dotted edge"];      
}

Adding the following to the generated js will work though.

options.physics = {
    enabled: false,
    stabilization: 10,
    barnesHut: {
        springLength: 200
    }
}