_do_attr(self, node) -> None
        Process an attribute.

def _do_attr(self, n, value):
        ''''_do_attr(self, node) -> None
        Process an attribute.'''

        W = self.write
        W(' ')
        W(n)
        W('="')
        s = string.replace(value, "&", "&amp;")
        s = string.replace(s, "<", "&lt;")
        s = string.replace(s, '"', '&quot;')
        s = string.replace(s, '\011', '&#x9')
        s = string.replace(s, '\012', '&#xA')
        s = string.replace(s, '\015', '&#xD')
        W(s)
        W('"')