Same string speed run challenge

Samestrspeed.py

while True:
    from random import sample
    from datetime import timedelta
    from time import time, sleep
    from os import system
    from string import ascii_letters, digits

    inp = int(input("String length : "))
    ainp = input("Upper or normal?")
    count = 1
    system("clear")
    now = time()
    while True:
        if ainp.lower() is "normal":
            old = "".join(sample(ascii_letters + digits, inp))
            new = "".join(sample(ascii_letters + digits, inp))
        else:
            old = "".join(sample(ascii_letters + digits, inp)).upper()
            new = "".join(sample(ascii_letters + digits, inp)).upper()
        if old == new:
            print(
                f"Found correct {new} & {old} Count {count}\n\rUse time {timedelta(seconds=time() - now)}",
                end="\r",
            )
            break
        print(
            f"Not correct {new} & {old} Count {count}\n\rUse time {timedelta(seconds=time() - now)}",
            end="\r",
        )
        count += 1
    sleep(2)
    print("\n\n",end="\r")