Manually annotate raw MNE objects on GUI, save annotation file, create events from annotations.

mne_manual_annotation.py

from mne import find_events, events_from_annotations
import mne

# get some raw data, replace by your own files
from moabb.datasets import BNCI2014001
sessions = BNCI2014001().get_data(subjects=[1])
raw = sessions[1]['session_T']['run_1']
ev = find_events(raw)

# Annotate plot
raw.plot(events=ev, color={'eeg': 'steelblue'})
# 1. press a to open annotation toolbox
# 2. directly type annotation name (e.g. inspi or expi)
# 3. click add new label and repeat for all annotation you need
# 4. drag and click on plot to create annotation, rght click to remove
# 5. Focus on annotation windows: Esc to finish annotations and Esc to quit plot

# Verify annotations
for ann in raw.annotations:
  print(f"{ann['description']}: onset={ann['onset']}, duration:{ann['duration']}")
  
# Save annotations
raw.annotations.save("annotations.csv")

# Convert annotation to events
ev_resp, ev_resp_id = events events_from_annotations(raw, event_id={'inspi': 1, 'expi': 2})