import httplib, mimetypes, urlparse

        def post_multipart(host, selector, fields, files):
            """
            Post fields and files to an http host as multipart/form-data.
            fields is a sequence of (name, value) elements for regular form
            fields. files is a sequence of (name, filename, value) elements
            for data to be uploaded as files Return the server's response
            page.
            """
            content_type, body = encode_multipart_formdata(fields, files)
            h = httplib.HTTP(host)
            h.putrequest('POST', selector)
            h.putheader('content-type', content_type)
            h.putheader('content-length', str(len(body)))
            h.endheaders()
            h.send(body)
            errcode, errmsg, headers = h.getreply()
            return h.file.read()

        def encode_multipart_formdata(fields, files):
            """
            fields is a sequence of (name, value) elements for regular form
            fields. files is a sequence of (name, filename, value) elements
            for data to be uploaded as files Return (content_type, body) ready
            for httplib.HTTP instance
            """
            BOUNDARY = '----------ThIs_Is_tHe_bouNdaRY_$'
            CRLF = '\r\n'
            L = []
            for (key, value) in fields:
                L.append('--' + BOUNDARY)
                L.append('Content-Disposition: form-data; name="%s"' % key)
                L.append('')
                L.append(value)
            for (key, filename, value) in files:
                L.append('--' + BOUNDARY)
                L.append('Content-Disposition: form-data; name="%s"; filename="%s"' % (key, filename))
                L.append('Content-Type: %s' % get_content_type(filename))
                L.append('')
                L.append(value)
            L.append('--' + BOUNDARY + '--')
            L.append('')
            body = CRLF.join(L)
            content_type = 'multipart/form-data; boundary=%s' % BOUNDARY
            return content_type, body

        def get_content_type(filename):
            return mimetypes.guess_type(filename)[0] or 'application/octet-stream'