Accessing a file in a subfolder on PhysioNet using pn_dir

I'm using wfdb 4.1.2, and when I try to run this code it fails with a 404:

import wfdb
record = wfdb.rdrecord('p1003/p10030753/s40735970/40735970', pn_dir='mimic-iv-ecg')

NetFileNotFoundError: 404 Error: Not Found for url: https://physionet.org/files/mimic-iv-ecg/1.0/40735970.hea

Looks like this relates to hacky path parsing which there is an open (semi-complete) PR for (#346).

I also tried:

import wfdb
record = wfdb.rdrecord('40735970', pn_dir='mimic-iv-ecg/1.0/p1003/p10030753/s40735970')

NetFileNotFoundError: 404 Error: Not Found for url: https://physionet.org/files/mimic-iv-ecg/1.0/p1003/p10030753/s40735970/40735970.hea

So I played with the path, and this ends up working:

import wfdb
record = wfdb.rdrecord('40735970', pn_dir='mimic-iv-ecg/1.0/files/p1003/p10030753/s40735970')

Seems a bit unintuitive to me that you have to put files in there, am I doing something wrong?

Start at wfdb.rdrecord and follow how record and pn_dir are combined for PhysioNet downloads. Reproduce both failing examples, then read the semi-complete PR #346 for the existing path-parsing approach. Done means nested MIMIC-IV-ECG records resolve without requiring an unintuitive files segment, with regression coverage for the shown paths.