Take the biggest value from array

[nilamo]

Hi,
I am new user on python, and I am new user here.
so, can you please help me to fix my python problem...

this table called tbl_a
===================
id    |   nama   |   num   |
===================
1    |  A          |    1,2   |
2    |  B          |    1,3   |
3    |  C          |    2     |
4    |  D          |  4,2,1  |
5    |  E          |  5,3     |
===================

i want to get the biggest value from that table, in that case should be 5 as the biggest value.
I have no idea to write a code.
thanks

Is it too late to redesign the table structure so it isn't so terrible?  num looks like a varchar, instead of a num like it claims, which is insanity.  This wouldn't even need to be a question you'd have to ask if the table was sane, as you could just have the database's index give you the answer lightning-fast: select max(num) from tbl_a where nama=%s.