def search_videos_by_tag(self, tag, category=None,<EOL>period='<STR_LIT>',<EOL>orderby='<STR_LIT>',<EOL>page=<NUM_LIT:1>, count=<NUM_LIT:20>):
url = '<STR_LIT>'<EOL>params = {<EOL>'<STR_LIT>': self.client_id,<EOL>'<STR_LIT>': tag,<EOL>'<STR_LIT>': period,<EOL>'<STR_LIT>': orderby,<EOL>'<STR_LIT>': page,<EOL>'<STR_LIT:count>': count<EOL>}<EOL>if category:<EOL><INDENT>params['<STR_LIT>'] = category<EOL><DEDENT>r = requests.get(url, params=params)<EOL>check_error(r)<EOL>return r.json()<EOL>
doc: http://open.youku.com/docs/doc?id=80