Simple Interest Calculator

# Programmer: Swinefire
# Date: 2-14-13

# The purpose of this program is to calculate the interest earned on a sum of money over a period of time.
# (It also provides two extra opportunities for the user to enter the data correctly without restarting the program if they make a mistake while entering it.)

def main():

    print "This program calculates the interest earned on a sum of money over a period of time."    # Explains the purpose of the program
    print

    # Asks user for needed information
    originalAmount = input("How much money will be earning interest? $")    # Assigns user-inputted amount earning interest to a variable
    interestPercent = input("What is the interest rate (percent)? ")        # Assigns the user-inputted interest rate to a variable
    years = input("How many years will the money be earning money? ")       # Assigns the user-inputted number of years the money will be earning interest to a variable

    # Prints entered information for accuracy
    print
    print "Original amount in bank: " + str(originalAmount)
    print "Interest rate: " + str(interestPercent) + "%"
    print "Years earning interest: " + str(years)
    print

    # Asks user if printed information is correct
    correctQuestion = raw_input("Does all of the information look correct (yes or no)? ")
    print

    if correctQuestion == "yes" or "Yes" or "YES":

            interestDecimal = (interestPercent * 0.01)                      # Converts the interest rate from a percentage to a decimal and assigns it to a variable
            interestAmount = (originalAmount * interestDecimal * years)     # Calculates the earned interest and assigns it to a variable
            totalAmount = (originalAmount + interestAmount)                 # Adds the earned interest to the original amount and assigns the sum to a variable

            # Prints all final amounts
            print
            print "If $" + str(originalAmount)  + " earns " + str(interestPercent) + "% interest for " + str(years) + " years, it would earn a total of $" + str(interestAmount) + " in interest, giving you a total of $" + str(totalAmount) + "."

    # Allows a chance to re-enter information if any was entered incorrectly
    elif correctQuestion == "no" or "No" or "NO":

        originalAmount = input("How much money will be earning interest? $")    # Assigns new user-inputted amount earning interest to a variable
        interestPercent = input("What is the interest rate (percent)? ")        # Assigns the new user-inputted interest rate to a variable
        years = input("How many years will the money earn interest? ")          # Assigns the new user-inputted number of years the money will be earning interest to a variable

        # Prints entered information for accuracy
        print
        print "Original amount in bank: " + str(originalAmount)
        print "Interest rate: " + str(interestPercent) + "%"
        print "Years earning interest: " + str(years)
        print

        # Asks user if printed information is correct
        correctQuestion = raw_input("Does all of the information look correct (yes or no)? ")
        print

        if correctQuestion == "yes" or "Yes" or "YES":

                interestDecimal = (interestPercent * 0.01)                  # Converts the interest rate from a percentage to a decimal and assigns it to a variable
                interestAmount = (originalAmount * interestDecimal * years) # Calculates the earned interest and assigns it to a variable
                totalAmount = (originalAmount + interestAmount)             # Adds the earned interest to the original amount and assigns the sum to a variable

                # Prints all final amounts
                print
                print "If $" + str(originalAmount)  + " earns " + str(interestPercent) + "% interest for " + str(years) + " years, it would earn a total of $" + str(interestAmount) + " in interest, giving you a total of $" + str(totalAmount) + "."

        # Allows a chance to re-enter information if any was entered incorrectly
        elif correctQuestion == "no" or "No" or "NO":

            originalAmount = input("How much money will be earning interest? $")    # Assigns new user-inputted amount earning interest to a variable
            interestPercent = input("What is the interest rate (percent)? ")        # Assigns the new user-inputted interest rate to a variable
            years = input("How many years will the money earn interest? ")          # Assigns the new user-inputted number of years the money will be earning interest to a variable

            # Prints entered information for accuracy
            print
            print "Original amount in bank: " + str(originalAmount)
            print "Interest rate: " + str(interestPercent) + "%"
            print "Years earning interest: " + str(years)
            print

            interestDecimal = (interestPercent * 0.01)                      # Converts the interest rate from a percentage to a decimal and assigns it to a variable
            interestAmount = (originalAmount * interestDecimal * years)     # Calculates the earned interest and assigns it to a variable
            totalAmount = (originalAmount + interestAmount)                 # Adds the earned interest to the original amount and assigns the sum to a variable

            # Prints all final amounts
            print
            print "If $" + str(originalAmount)  + " earns " + str(interestPercent) + "% interest for " + str(years) + " years, it would earn a total of $" + str(interestAmount) + " in interest, giving you a total of $" + str(totalAmount) + "."


main()