check input in list

def find_type(source):
    'function to examine string and determine if it contains'
    'a viable float, integer or string and return appropriate'
    'type accordingly'
    try:
        value = None
        value = float(source)  # try to convert source to float
        value = int(source)  # float worked, let's try integer
    except ValueError:  # not float or integer
        if not value:  # cast to float failed so neither float nor string
            value = source
    return value

mylist = ['Hello', 123, 456.7]

while True:
    response = input('Enter something (or just return to exit: ')
    if not response:
        break
    value = find_type(response)
    print(f'You entered {value} ({type(value).__name__}), which is '
          f'{"" if value in mylist else "not "}in my list')