How to declare nonlocal dynamically in closures

my purpose is to declare dynamically, either b or c

def t1():
    b = 1
    c = 2
    def t2():
       s = "nonlocal "+ "b"
       exec(s)

will make an error SyntaxError: nonlocal declaration not allowed at module level
is there a solution

Sep.17,2021
MySQL Query : SELECT * FROM `codeshelper`.`v9_news` WHERE status=99 AND catid='6' ORDER BY rand() LIMIT 5
MySQL Error : Disk full (/tmp/#sql-temptable-64f5-1ea7953-1e68.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
MySQL Errno : 1021
Message : Disk full (/tmp/#sql-temptable-64f5-1ea7953-1e68.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
Need Help?