Python - Graphviz force rank to be at least the same

Question

What I am Doing

I am making a course tree in graphviz. Each course is a node and prerequisites and corequisites are signified as edges between nodes.

What is working

The layout does a pretty good job of putting courses below their prerequisites

What is not working

I have put constraint='false' on corequisites. However, I want corequisites to be on at least the same rank as each other (aka, corequisites should either point sideways and/or downwards).

Code

for course in data['CPEN']['courses']:
    cpen.node(course['id'])

for course in data['CPEN']['courses']:
    for pre in course['prerequisites']:
        cpen.edge(pre, course['id'], color='Black')
    for co in course['corequisites']:
        cpen.edge(co, course['id'], color='Blue', constraint='false')

cpen.render(f'test-output/cpen_{time.time()}.gv', view=True)

Current Output

Math 101 as a corequisite of Math 152, so they should be on at least the same rank (not necessarily the same rank). However, the arrow is pointing up because the edge is not used in ranking due to no constraint.

Questions

How do I make a node be on the same or higher rank than another node

How do I set the rank of a node to a number? (How do I set a second year course to be at least rank 3?)