import threading
import time
import sys

#not sure if you actually need this, but oh well
print_lock = threading.Lock()

def print_stuff():
    for _ in range(5):
        time.sleep(1)
        with print_lock:
            print("Hello" + " "*20) #put some spaces at the end to make sure the progress message is overwritten

threading.Thread(target=print_stuff).start()

for i in range(101):
    with print_lock:
        print(f"{i}% complete.\r", end="")
    time.sleep(0.033)