Method set_boundary

Lib/email/message.py:879–923

Set the boundary parameter in Content-Type to 'boundary'. This is subtly different than deleting the Content-Type header and adding a new one with a new boundary parameter via add_header(). The main difference is that using the set_boundary() method preserves the or

(self, boundary)

        return utils.collapse_rfc2231_value(boundary).rstrip()

    def set_boundary(self, boundary):
        """Set the boundary parameter in Content-Type to 'boundary'.

        This is subtly different than deleting the Content-Type header and
        adding a new one with a new boundary parameter via add_header().  The
        main difference is that using the set_boundary() method preserves the
        order of the Content-Type header in the original message.

        HeaderParseError is raised if the message has no Content-Type header.
        """
        missing = object()
        params = self._get_params_preserve(missing, 'content-type')
        if params is missing:
            # There was no Content-Type header, and we don't know what type
            # to set it to, so raise an exception.
            raise errors.HeaderParseError('No Content-Type header found')
        newparams = []
        foundp = False
        for pk, pv in params:
            if pk.lower() == 'boundary':
                newparams.append(('boundary', '"%s"' % boundary))
                foundp = True
            else:
                newparams.append((pk, pv))
        if not foundp:
            # The original Content-Type header had no boundary attribute.
            # Tack one on the end.  BAW: should we raise an exception
            # instead???
            newparams.append(('boundary', '"%s"' % boundary))
        # Replace the existing Content-Type header with the new value
        newheaders = []
        for h, v in self._headers:
            if h.lower() == 'content-type':
                parts = []
                for k, v in newparams:
                    if v == '':
                        parts.append(k)
                    else:
                        parts.append('%s=%s' % (k, v))
                val = SEMISPACE.join(parts)
                newheaders.append(self.policy.header_store_parse(h, val))

            else:
                newheaders.append((h, v))
        self._headers = newheaders

    def get_content_charset(self, failobj=None):
        """Return the charset parameter of the Content-Type header.