Drop all postgresql schemas in a batch

drop-all-schemas.sql

CREATE OR REPLACE FUNCTION drop_all ()
   RETURNS VOID  AS
   $$
   DECLARE rec RECORD;
   BEGIN
       -- Get all the schemas
        FOR rec IN
        SELECT nspname FROM pg_catalog.pg_namespace WHERE (nspname != 'public') and (nspname NOT LIKE 'pg_%') and (nspname != 'information_schema') LIMIT 50
           LOOP
             EXECUTE format('DROP SCHEMA "%s" CASCADE', rec.nspname);
           END LOOP;
           RETURN;
   END;
   $$ LANGUAGE plpgsql;

SELECT drop_all();

Courtesy: https://gist.github.com/xlucasdemelo/51d8d4a94e9a402daadf0579b0144a76