feat(graphviz): support custom node and edge attributes in ibis.visualize

[peter-gy]

Description of changes

Enables the customization of graphviz graphs produced by ibis.visualize by exposing node_attr and edge_attr as optional keyword arguments. Changing node shapes, fonts and font sizes can be highly useful when dealing with complex expression graphs.

The default attributes (DEFAULT_NODE_ATTRS, DEFAULT_EDGE_ATTRS) are still considered, but the user-defined ones will take precedence.

[cpcloud]

Nice!

Do you have a sweet image you can show that takes advantage of these shiny new parameters?

[peter-gy]

Nice!

Do you have a sweet image you can show that takes advantage of these shiny new parameters?

Of course. From now on, nothing stops us from committing cardinal sins like using Comic Sans MS for edge labels :)

import ibis


left = ibis.table(dict(a="int64", b="string"), name="left")
right = ibis.table(dict(b="string", c="int64", d="string"), name="right")
expr = (
    left.inner_join(right, "b")
    .select(left.a, b=right.c, c=right.d)
    .mutate(
        arrays=ibis.array([1, 2, 3]),
    )
)
expr.visualize(
	label_edges=True,
	node_attr={"shape":"hexagon", "color":"green", "fontname": "Roboto Mono"},
	edge_attr={"fontsize": "12", "fontname": "Comic Sans MS"}
)

[lostmygithubaccount]

that's going in the 9.0 blog, thanks! 😂

[cpcloud]

I'm adding a how-to for ibis.expr.visualize.to_graph and will add this image there.

[peter-gy]

Awesome :)