Understanding Python descriptors #2

snippet_2.py

from validate_email import validate_email
    
class EmailField(object):
    def __get__(self, instance, owner):
        return self.value
 
    def __set__(self, instance, value):
        validate_email(value)
        self.value = value
        
class User(object):
    email = EmailField()
    
    def __init__(self):
        pass