Basic loading effect.

progression.py

import time
def progression_bar(total_time=5, loading_msg="Loading...", end_msg="Completed."):

    max_str = max(len(loading_msg), len(end_msg))
    loading_msg = loading_msg.ljust(max_str)
    end_msg = end_msg.ljust(max_str)
    num_bar = 10
    sleep_intvl = total_time/num_bar
    for i in range(1,num_bar+1):
        print(f"\r{loading_msg} {i/num_bar:.1%}", end="")
        time.sleep(sleep_intvl)
    print(f"\r{end_msg}")

if __name__ == "__main__": 
    progression_bar()
    print('Hello World!')