Error when loading reference draws on Python +3.9

[Red-Portal]

The following basic use case fails on Python 3.13:

from posteriordb import PosteriorDatabaseGithub

pdb   = PosteriorDatabaseGithub()
post  = pdb.posterior("diamonds-diamonds")
ref_samples = post.reference_draws()

Here's the error code:

Traceback (most recent call last):
  File "/home/krkim/Projects/diamonds/test.py", line 16, in <module>
    ref_samples = post.reference_draws()
  File "/home/krkim/.pyenv/versions/diamonds_env/lib/python3.13/site-packages/posteriordb/posterior.py", line 41, in reference_draws
    with ZipFile(self.reference_draws_file_path() + ".zip", "r") as z:
                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~
TypeError: unsupported operand type(s) for +: 'PosixPath' and 'str'

Apparently, the restrictions on the operators on path objects became stricter since Python 3.9, and this is not allowed anymore.

[MansMeg]

Thanks. Can you try to do a PR that fixes this? Otherwise we can try to fix this.

[Red-Portal]

Hi, I tried fixing that issue by fixing

with ZipFile(self.reference_draws_file_path() + ".zip", "r") as z:

to

with ZipFile(self.reference_draws_file_path().with_suffix(".zip"), "r") as z:

but I hit a different error:

>>> post.reference_draws()
Traceback (most recent call last):
  File "<python-input-17>", line 1, in <module>
    post.reference_draws()
    ~~~~~~~~~~~~~~~~~~~~^^
  File "/home/krkim/Projects/diamonds/../posteriordb-python/src/posteriordb/posterior.py", line 41, in reference_draws
    with ZipFile(self.reference_draws_file_path().with_suffix(".zip"), "r") as z:
         ~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/krkim/.pyenv/versions/3.13.5/lib/python3.13/zipfile/__init__.py", line 1367, in __init__
    self.fp = io.open(file, filemode)
              ~~~~~~~^^^^^^^^^^^^^^^^
FileNotFoundError: [Errno 2] No such file or directory: '/home/krkim/.posteriordb/posterior_database/reference_posteriors/draws/draws/eight_schools-eight_schools_noncentered.zip'

It seems like the reference draws are not being downloaded? Indeed the path .posteriordb/posterior_database/reference_posteriors/draws does not seem contain any .zip file. (It does contain the info files.)

[MansMeg]

Great! Well take a look asap.