[python] spin animation during long running code

main.py

# 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.