<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def avg(self, property):
 """Getting average according to given property :@param property :@type property: string :@return average: int/float """

        self.__prepare()
        return self.sum(property) / self.count()