Looking for a PL/PGSQL function to return N columns

Run in a PL/pgSQL a function to return N columns and put in a view or something that allow to get the table with the N column updated without human intervention.

Using the below code from:
https://stackoverflow.com/questions/75594224/

---sample data 
DROP TABLE IF EXISTS  split_clm;
CREATE TEMP TABLE  split_clm(
id integer PRIMARY KEY,
name text,
hobby text, 
value int
);
INSERT INTO  split_clm (id, name, hobby,value) VALUES
(1, 'Rene', 'Python, Monkey_Bars','5'),
(2, 'CJ', 'Trading, Python','25'),
(3, 'Herlinda', 'Fashion','15'),
(4, 'DJ', 'Consutling, Sales','35'),
(5, 'Martha', 'Social_Media, Teaching','45'),
(6, 'Doug', 'Leadership, Management','55'),
(7, 'Mathew', 'Finance, Emp_Engagement','65'),
(8, 'Mayers', 'Sleeping, Coding, Crossfit','75'),
(9, 'Mike', 'YouTube, Athletics','85'),
(10, 'Peter', 'Eat, Sleep, Python','95'),
(11, 'Thomas', 'Read, Trading, Sales','105');
/****query****/
--1NF <done>
DROP TABLE IF EXISTS  split_clm_Nor;
CREATE TEMP TABLE     split_clm_Nor  AS	
SELECT id, name, unnest(string_to_array(hobby, ', ')) AS Ivalues , value
FROM  split_clm
ORDER BY id;
-- 
--Select * from    split_clm_Nor limit 6; ---
---ver 2.0
DROP TABLE IF EXISTS  split_clm_Nor2;
CREATE TEMP TABLE      split_clm_Nor2  AS
SELECT id, name, lower(unnest(string_to_array(hobby, ', '))) AS Ivalues , value,count(1)  as "Case_Volume"
FROM  split_clm
GROUP BY 1,2,3,4
ORDER BY id
;
Select * from    split_clm_Nor2  ; 
---------------------------
DROP TABLE IF EXISTS   tmpTblTyp2 CASCADE ; 
DO LANGUAGE plpgsql $$ 
DECLARE v_sqlstring VARCHAR  = ''; 
BEGIN 
v_sqlstring := CONCAT( 'CREATE  TABLE  tmpTblTyp2 AS SELECT '   
,(SELECT  STRING_AGG( CONCAT('NULL::int AS ' , ivalues )::TEXT , ' ,' ORDER BY ivalues )::TEXT
FROM (SELECT DISTINCT ivalues  FROM  split_clm_Nor2) a
)
,' LIMIT 0 '    
) ; -- RAISE NOTICE '%', v_sqlstring ;  
EXECUTE( v_sqlstring ) ; END $$; 
--------------------------------------------
DROP TABLE IF EXISTS  tmpMoJson ;
CREATE TEMP TABLE     tmpMoJson  AS
--CREATE TEMP TABLE tmpMoJson AS
SELECT 
name AS name
,(json_build_array( mivalues )) AS js_mivalues_arr
,json_populate_recordset ( NULL::tmpTblTyp2 /** use temp table as a record type!!*/
, json_build_array( mivalues )  /** builds row-type column that can be expanded with (jprs).* */
) jprs  
FROM ( SELECT name
,json_object_agg(ivalues,value) AS mivalues 
FROM split_clm_Nor2
GROUP BY 1
ORDER BY 1
) a
;
Select * from    tmpMoJson  ; 
SELECT  
name
,(ROW((jprs).*):: tmpTblTyp2).* -- explode the composite type row
--, js_mivalues_arr /** optional **/
FROM  tmpMoJson ;

Expecting get that table continue update

You can't create a function that returns a dynamic number of columns without hard coding the list of columns at some place (either when calling the function or when defining the function).

The best (only?) option I see, is to create a view that is based on the content of the table. You can then call that view each time the table changes to create a new view with the updated list of columns.

create function create_clm_view()
returns void
as
$body$
declare
l_sql text;
l_columns text;
l_hobby_name text;
begin
l_sql := 'select name, ';
-- build the list of columns based on the distinct hobbies
select string_agg(format('%L = any(hobbies) as %I', x.hobby_name, x.hobby_name), ', ' order by hobby_name)
into l_columns
from (
select distinct t.hobby_name
from split_clm s
cross join unnest(regexp_split_to_array(s.hobby, '\s*,\s*')) as t(hobby_name)
) x;
-- build the final SELECT of the view with the generated columns
l_sql := l_sql || l_columns ||
$sql$ from ( select name, regexp_split_to_array(hobby, '\s*,\s*') as hobbies from split_clm ) t $sql$ ;
-- recreate the view
execute 'drop view if exists clm_view cascade';
execute 'create view clm_view as '||l_sql;    
end;
$body$ 
language plpgsql;

This will build a view that looks something like this:

select name, 
'Athletics' = any(hobbies) as "Ahtletics",
'Coding' = any(hobbies) as "Coding",  
.....
from ( select name, regexp_split_to_array(hobby, '\s*,\s*') as hobbies from split_clm ) t;

Then run:

select create_normalized_view();

and to see the content:

select *
from clm_view;

Depending on how often the table is updated, you could call that function from a trigger or a cron job that updates the view in regular intervals.

Online example