A Simple Loading Animation Decorator For the Command Line Using Python 3

Loading_animation.py

"""
  This program is designed to create
  and animate a simple loading animation.
"""

from sys import stdout as terminal
from time import sleep
from itertools import cycle
from threading import Thread


def loading_animation(running_text: str = "Running", finished_text: str = "Done!"):

    diff = len(running_text) - len(finished_text) + 2
    spaces = " " * diff if diff > 0 else ""

    def wrapper(f):
        def wrapped(*args, **kwargs):
            done = False

            def animation():
                for c in cycle(['|', '/', '-', '\\']):
                    if done:
                        break
                    terminal.write(f'\r{running_text} ' + c)
                    terminal.flush()
                    sleep(0.1)
                terminal.write(f'\r{finished_text}' + spaces + "\n")
                terminal.flush()

            t = Thread(target=animation)
            t.start()

            result = f(*args, **kwargs)
            done = True
            t.join()
            return result
        return wrapped
    return wrapper


  # Usage examples
if __name__ == "__main__":
    
    # Custom text
    @loading_animation("Sleeping", "Had a good nap")
    def test_function(time: int):
        sleep(time)
        
    # Default text
    @loading_animation()
    def test_function2(time: int):
        sleep(time)

    test_function(3)
    test_function2(3)