I.e., you pass in the constant value when initializing, then all values get converted to that constant value.

This is only really useful for funny situations, like:

fromEmailValidator = ValidateAny(
                         ValidEmailAddress(),
                         Constant('unknown@localhost'))

In this case, the if the email is not valid 'unknown@localhost' will be used instead. Of course, you could use if_invalid instead.

Examples:

>>> Constant('X').to_python('y')
'X'

Messages

badType:

The input must be a string (not a %(type)s: %(value)r)

empty:

Please enter a value

noneType:

The input must be a string (not None)