spinning animation during long running code

# author: Bartlomiej "furas" Burek (https://blog.furas.pl)
# date: 2021.06.10
# https://stackoverflow.com/questions/67904508/custom-animation-while-python-connects-to-remote-mysql-database

# spinning animation during long running code

import threading
import time

# single char \ has special meaning in string so it needs \\
# or string needs prefix `r` for `raw` string: animation=r'|/-\'
def spinning(delay=0.1, animation='|/-\\'):
    global running

    running = True

    length = len(animation)
    index = 0

    while running:
        print(animation[index], end='\r', flush=True)  # it may need flush to send on screen when there is no `\n`
        index = (index + 1) % length  # modulo `%`
        time.sleep(delay)

def connecting():
    """Long running code."""
    time.sleep(5)

# --- main ---

#t = threading.Thread( target=spinning, args=(0.05, '-/|\\'))
#t = threading.Thread(target=spinning, kwargs={'delay': 0.05, 'animation': '-/|\\'})
t = threading.Thread(target=spinning)

print('start')
running = True
t.start()

connecting()

running = False
t.join()
print('end')

# to run animation again you have to create `thread` again.