(self, prefix, uri)
Begin the scope of a prefix-URI Namespace mapping.

        The information from this event is not necessary for normal
        Namespace processing: the SAX XML reader will automatically
        replace prefixes for element and attribute names when the
        http://xml.org/sax/features/namespaces feature is true (the
        default).

        There are cases, however, when applications need to use
        prefixes in character data or in attribute values, where they
        cannot safely be expanded automatically; the
        start/endPrefixMapping event supplies the information to the
        application to expand prefixes in those contexts itself, if
        necessary.

        Note that start/endPrefixMapping events are not guaranteed to
        be properly nested relative to each-other: all
        startPrefixMapping events will occur before the corresponding
        startElement event, and all endPrefixMapping events will occur
        after the corresponding endElement event, but their order is
        not guaranteed.
Begin the scope of a prefix-URI Namespace mapping.
Begin the scope of a prefix - URI Namespace mapping .
def startPrefixMapping(self, prefix, uri):
        """Begin the scope of a prefix-URI Namespace mapping.

        The information from this event is not necessary for normal
        Namespace processing: the SAX XML reader will automatically
        replace prefixes for element and attribute names when the
        http://xml.org/sax/features/namespaces feature is true (the
        default).

        There are cases, however, when applications need to use
        prefixes in character data or in attribute values, where they
        cannot safely be expanded automatically; the
        start/endPrefixMapping event supplies the information to the
        application to expand prefixes in those contexts itself, if
        necessary.

        Note that start/endPrefixMapping events are not guaranteed to
        be properly nested relative to each-other: all
        startPrefixMapping events will occur before the corresponding
        startElement event, and all endPrefixMapping events will occur
        after the corresponding endElement event, but their order is
        not guaranteed."""
def startPrefixMapping ( self , prefix , uri ) :