Move Around

1. After login, run the command "curses_6.py". The program shows a star ('*') which is moving around a rectangle.
2. You may start from a loop which moves the star along a side. Use the "curses" library to write a program, which shows a star moving towards the left
3. The flowchart looks like this:
   
4. To move around the four sides of a rectangle, actually you need to decompose the problem to 4 loops.