def escape_attribute(value, encoding):
    """Escape an attribute value using the given encoding."""
    if "&" in value:
        value = value.replace("&", "&amp;")
    if "<" in value:
        value = value.replace("<", "&lt;")
    if '"' in value:
        value = value.replace('"', "&quot;")
    return value.encode(encoding, "xmlcharrefreplace")