Write a python program that asks a user to enter the value for three resistors R$1,$ R$2$ and R$3.$ Include one or more functions that:

Validates the data by ensuring a positive numeric value was entered. If the entered number is negative or zero, a message should display that this is not a valid resistance. Please enter a positive number.

Calculates the total resistance when R$1$ & R$2$ & R$3$ are in series configuration. Then display a message: $$if R$1,$ R$2$ and R$3$ are in series, then the total resistance is$\_\_\_\_\_\_.$ Refer to the figure below. You can use the following equation. R$\_$total$=$R$1+$R$2+$R$3$