import re

pattern = re.compile(

    r'^(([a-zA-Z]{1})|([a-zA-Z]{1}[a-zA-Z]{1})|'

    r'([a-zA-Z]{1}[0-9]{1})|([0-9]{1}[a-zA-Z]{1})|'

    r'([a-zA-Z0-9][-_.a-zA-Z0-9]{0,61}[a-zA-Z0-9]))\.'

    r'([a-zA-Z]{2,13}|[a-zA-Z0-9-]{2,30}.[a-zA-Z]{2,3})$'

)

def is_valid_domain(value):

    """

    Return whether or not given value is a valid domain.

    If the value is valid domain name this function returns ``True``, otherwise False

    :param value: domain string to validate

    """

    return True if pattern.match(value) else False