I want to get the values ​output from a process that has been executed once

Question

from pwn import *
import subprocess
import sys

def disas(a):
    context.terminal = ['gnome-terminal', '-x', 'sh', '-c']
    p = gdb.debug(a,gdbscript='disas main')
    print(p)

print("[*] Please same directory ELF &  StackVisual file")
a = input("[*] process : ").strip('\n')

disas(a)

It is running on linux with python. I want to put the assembly language code of the stack part in a variable and output it, but I don't know how.

I tried to get the string printed once using subprocess, but it failed because I didn't know how to get the string to the already executed process.