in reply to list of lists?

"...I want more information..."

What about a tiny database like SQLite?

sqlite3 sites.db "create table if not exists sites(id INTEGER PRIMARY +KEY, zip TEXT, city TEXT, url TEXT);" sqlite3 sites.db SQLite version 3.32.3 2020-06-18 14:16:19 Enter ".help" for usage hints. sqlite> .schema sites CREATE TABLE sites(id INTEGER PRIMARY KEY, zip TEXT, city TEXT, url T +EXT); sqlite> .header on sqlite> .mode column sqlite> pragma table_info('sites'); cid name type notnull dflt_value pk ---------- ---------- ---------- ---------- ---------- ---------- 0 id INTEGER 0 1 1 zip TEXT 0 0 2 city TEXT 0 0 3 url TEXT 0 0 sqlite> insert into sites (zip, city, url) values ('12345', 'Entenhausen', 'kg +b.net'); sqlite> select * from sites; id zip city url ---------- ---------- ----------- ---------- 1 12345 Entenhausen kgb.net sqlite>

See also DBI and DBD::SQLite. Best regards, Karl

«The Crux of the Biscuit is the Apostrophe»