Displaying lists in treemaps or hovertemplates in plotly express

I’m attemping to display a list of values in plotly express

I have the list saved as a single string. It’s made up of 10-20 substrings broken up by commas

The default is for the list to display horizontally which doesn’t work well.

Is there a workaround for this to be displayed vertically.

value is something like “a,b,c,d,e,f,g,h,i”

I’d like it to be displays

“a,
b,
c,
d,
e,
f”

In the treemap I want to display the list in the final node. I’m struggling to think of a workaround.