Start IDLE and open the mpg$.$py file that$$s in this folder: murach$/$python$/$exercises$/$ch$03$

$2.$ Test the program with valid and invalid values. $3.$ Enhance the program so it lets the user repeat the entries and get the miles per gallon for more than one trip. To do that, use a while loop.

$4.$ Modify this program so it gets the cost of a gallon of gas as another entry from the user, and validate this entry before using it in your calculations. If all three entries are valid, calculate the total gas cost and the cost per mile, and display the results on the console.