MRG: Fix amending a dataset when new columns are being added to participants.tsv

[hoechenberger]

Closes #1104

MWE:

from pathlib import Path
import pandas as pd
import mne
from mne_bids import write_raw_bids, BIDSPath

BIDS_ROOT = Path('/tmp/bids-test')

sample_data_path = mne.datasets.sample.data_path(download=False)
raw_path = sample_data_path / 'MEG' / 'sample' / 'sample_audvis_raw.fif'
raw = mne.io.read_raw_fif(raw_path)

bids_path = BIDSPath(
    task='test',
    suffix='meg',
    extension='.fif',
    datatype='meg',
    root=BIDS_ROOT,
)

# Need to write >1 participants first
bids_path.update(subject='01')
write_raw_bids(raw, bids_path, overwrite=True)

bids_path.update(subject='02')
write_raw_bids(raw, bids_path, overwrite=True)

# Drop two columns
participants_csv = pd.read_csv(BIDS_ROOT / "participants.tsv", sep='\t')
participants_csv = participants_csv.drop(columns=['weight', 'height'])
participants_csv.to_csv(BIDS_ROOT / "participants.tsv", index=False, na_rep="n/a", sep="\t")

# Write additional participant
bids_path.update(subject='03')
write_raw_bids(raw, bids_path, overwrite=True)

On main:

Traceback (most recent call last):
[...]
  File "/Users/hoechenberger/Development/mne-bids/mne_bids/write.py", line 1804, in write_raw_bids
    _participants_tsv(
  File "/Users/hoechenberger/Development/mne-bids/mne_bids/write.py", line 447, in _participants_tsv
    data = _combine_rows(orig_data, data, 'participant_id')
  File "/Users/hoechenberger/Development/mne-bids/mne_bids/tsv_handler.py", line 44, in _combine_rows
    data[key] = [data[key][n_rows - 1 - idx] for idx in idxs]
  File "/Users/hoechenberger/Development/mne-bids/mne_bids/tsv_handler.py", line 44, in <listcomp>
    data[key] = [data[key][n_rows - 1 - idx] for idx in idxs]
IndexError: list index out of range

Passes with this PR branch.

• Add tests
• Add changelog entry

PR Description

Merge checklist

Maintainer, please confirm the following before merging.
If applicable:

• All comments are resolved
• This is not your own PR
• All CIs are happy
• PR title starts with [MRG]
• whats_new.rst is updated
• New contributors have been added to CITATION.cff
• PR description includes phrase "closes <#issue-number>"

[hoechenberger]

This is just aesthetics.

[hoechenberger]

participant_id column must always be present so just use this one.

[Codecov]

Codecov Report

Merging #1113 (af951ce) into main (8b20f3a) will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##             main    #1113   +/-   ##
=======================================
  Coverage   95.03%   95.04%           
=======================================
  Files          40       40           
  Lines        8668     8670    +2     
=======================================
+ Hits         8238     8240    +2     
  Misses        430      430           

Impacted Files	Coverage Δ
mne_bids/tests/test_write.py	89.31% <100.00%> (+0.15%)	⬆️
mne_bids/write.py	97.28% <100.00%> (-0.01%)	⬇️
mne_bids/commands/tests/test_cli.py	96.61% <0.00%> (-1.70%)	⬇️

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