Aurora Saturday 18:00 Python Homework 20.07.11.

Question：

Continue to program the code we made in the class. Try to make back (<-) button work as following:

• if there are more than 1 digits in the display, you can delete the digit form right side
• if there is only 1 digits in the display but the digits is not 0, the digit will be changed into 0
• if there is only 0 displayed, the display will remain as 0 when you click the back button.