Validators are associated with keys either with a class syntax, or as keyword arguments (class syntax is usually easier). Something like:

class MySchema(Schema):
    name = Validators.PlainText()
    phone = Validators.PhoneNumber()

These will not be available as actual instance variables, but will be collected in a dictionary. To remove a validator in a subclass that is present in a superclass, set it to None, like:

class MySubSchema(MySchema):
    name = None

Messages

badType:

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

empty:

Please enter a value

missingValue:

Missing value

noneType:

The input must be a string (not None)

notExpected:

The input field %(name)s was not expected.