mtimes_to_paths = {}
for path in [path for path in os.listdir(os.path.dirname(bak_prefix))
if path.startswith(os.path.basename(bak_prefix))]:
+ path = os.path.dirname(bak_prefix) + f'/{path}'
mod_time = os.path.getmtime(path)
print(f'DEBUG pre-exists: {path} {mod_time}')
mtimes_to_paths[str(datetime.fromtimestamp(mod_time))] = path