def _get_api_sig(args):
tmp_sig = api_secret<EOL>for i in args:<EOL><INDENT>tmp_sig = tmp_sig + i[<NUM_LIT:0>] + i[<NUM_LIT:1>]<EOL><DEDENT>api_sig = hashlib.md5(tmp_sig.encode('<STR_LIT:utf-8>')).hexdigest()<EOL>return '<STR_LIT>', api_sig<EOL>
Flickr API need a hash string which made using post arguments

    :param args: Arguments of the flickr request
    :type args: list of sets
    :return: api_sig, ex: ('api_sig', 'abcdefg')
    :rtype: tuple