how to show progress bar in terminal code example

Example: how to make loading in python

import time
import sys

done = 'false'
#here is the animation
def animate():
    while done == 'false':
        sys.stdout.write('\rloading |')
        time.sleep(0.1)
        sys.stdout.write('\rloading /')
        time.sleep(0.1)
        sys.stdout.write('\rloading -')
        time.sleep(0.1)
        sys.stdout.write('\rloading \\')
        time.sleep(0.1)
    sys.stdout.write('\rDone!     ')

animate()
#long process here
done = 'false'