Update variable value in variables Python file

I have a variables.py file with a key TOKEN= 123456. I need to update that value dynamically when ever it required.

The file Constants.py reads:

#!/usr/bin/env python
# encoding: utf-8
"""
variables.py
"""

TOKEN= 50

And refresh_tok.py

#!/usr/bin/env python
# encoding: utf-8
"""
refresh_tok.py
"""
import variables

def refresh_token():
    print(variables.TOKEN) // previous value 50
    change_constant(variables.TOKEN, 100)
    print(variables.TOKEN) // value I am expecting is 100 but it says 50


def change_constant(match_string, replace_string):
    read_file = open("variables.py", "rt")
    read_data = read_file.read()
    read_data = read_data.replace(match_string, replace_string)
    read_file.close()
    
    write_file = open("variables.py", "wt")
    write_file.write(read_data)
    write_file.close()

Value that I am expecting in 2nd print statement in refresh_tok.py is 100 but it is still on previous value and print 50 rather then 100.