Sum, Subtraction and Multiplication Basic Python program

1. Here i used dictionary  mapping to achieve switch statement.
2. Used format method of the string.
3. Print multiple string in single print method by """.
4. Used while loop to iterate over the user input.

def sum():

    try:

        number1=float(input('Please enter first Number'))

        number2=float(input('Please enter second Number'))

        print('Sum is:',number1+number2)

    except Exception  as e:

        print('Invalid value is passed to sum.')

    

def subtraction():

    try:

        number1=float(input('Please enter first Number'))

        number2=float(input('Please enter second Number'))

        subtractionValue=number1-number2

        print('Subtraction is:{subtractionValue}'.format(subtractionValue=subtractionValue))

    except Exception  as e:

        print('Invalid value is passed to sum.')

def multiplication():

    try:

        number1=float(input('Please enter first Number'))

        number2=float(input('Please enter second Number'))

        print('Multiplication is:{0}'.format(number1*number2))

    except Exception  as e:

        print('Invalid value is passed to sum.')

options={

        1:sum,

        2:subtraction,

        3:multiplication

    }

def displayWhatUserCanInput():

    print("""

            Please enter number

            1. For Sum

            2. For Subtraction

            3. For Multiplication

            """)

    try:

        i=int(input("Enter the option 1,2 or 3"))

        func=options.get(i,'Invalid value')

        func()

    except Exception as e:

        print('Invalid entry is passed.')

def whileloop():

    displayWhatUserCanInput()

    done=False

    while done==False:

        userinput=input('Enter 5 to exit and any other number to continue.')

        if  int(userinput)==5:

            print('Bye!')

            done=True

        else:

            displayWhatUserCanInput()

            done=False

whileloop()