PlPython3 longest common prefix aggregate

longest_pommon_prefix.sql

drop function lcp_text(text,text) cascade;

create function lcp_text(acc text, b text) 
returns text as $$

import itertools as i

if acc is None:
  return b

return ''.join(list(
   a for (a, _) 
   in i.takewhile(lambda x: x[0] == x[1], zip(acc, b))))   
$$ language plpython3u;

create aggregate LCP(text) (
stype = text,
sfunc = lcp_text
);

select lcp_text('aa', 'aaad');