Lists indices

def index_list(self):
        '''
        Lists indices
        '''
        request = self.session
        url = 'http://%s:%s/_cluster/state/' % (self.host, self.port)
        response = request.get(url)
        if request.status_code==200:
            return response.get('metadata',{}).get('indices',{}).keys()
        else:
            return response