[mkl]

Latex seems way better than either to me (but then, I know Latex). Certainly Latex makes it much easier to get consistency and precision. For your use-case, generate Latex code from a template using Python or whatever, substituting in what you need, then compile the Latex into a PDF. If you need graphical elements or precise layout control, use the Latex package TikZ.

If what you need is very simple (e.g. no word wrapping, same number of variable strings in the same positions), even manipulating the code of a template PDF directly is not too hard. This library would help with that.