This code should draw a rectangle, but it produces a blank page:

from PIL import PSDraw

with open('output.ps', 'wb') as file:
    ps = PSDraw.PSDraw(file)
    ps.begin_document('TEST')
    ps.rectangle((1 * 72, 4 * 72, 3 * 72, 2 * 72))
    ps.end_document()

I inspected the PostScript that it produced and it didn't make a whole lot of sense to me (I've worked with it in the past) until I realised that the parameters on the PostScript stack were in the wrong order.

The PostScript says "72 288 M 216 144 0 Vr" when it should say "72 288 M 0 216 144 Vr", i.e. it's "left top M width height 0 Vr" instead of "left top M 0 width height Vr".

When I edited the PostScript, I got the expected result.