map/cgi-bin/save_data.py

#!/usr/bin/python3

import cgi
import cgitb
from pathlib import Path
cgitb.enable()

form = cgi.FieldStorage()

print('Content-Type: text/plain\n')

content = form.getfirst('content')
map_id = form.getfirst('map_id')

with open(Path('..') / 'data' / f'markers-{map_id}.json', 'w') as f:
  f.write(content)

print(content)