def __init__(self, field, expression):
        """
        Object contructor.

        :param str field: The name of the field in the row that must be match against the expression.
        :param str expression: The expression.
        """
        self._field = field
        """
        The name of the field in the row that must be match against the expression.

        :type: str
        """

        self._expression = expression
        """
        The expression.

        :type: str
        """
def __init__ ( self , field , expression ) : self . _field = field self . _expression = expression
Object contructor.

        :param str field: The name of the field in the row that must be match against the expression.
        :param str expression: The expression.