Changes

: Attached code Remember we define the sum_times() function to add to time objects and return their sum? After we moved the function definition under the class definition in lab7d.py, it became a class function, and method for the time object. It can be invoked by using the Time.sum_times(t1,t2) syntax or t1.sum_times(t2) syntax. How, there is any way to invoke it by using a special function which ties to the '+' arithmetic operator .: The '+' and operator is bind to the special function of an object's __add__() method. If we attached the same code we have for the sum_times() function to the special function __add__() for the time object, the we can use the '-+' operator to support tell the python interpreter to perform sum operation on thw time object.: Changing or specifying the behaviour of adding an operator so that it works with programmer-defined types is called '''operator overloading'''. : Let's add the appropriate code to the __add__ function to overload the '+' operator so that we can use an arithmetic expression to tell the python interpreter to add two time object.::* Associate the following code to the __add__ method for Time class in lab7d.py:<source lang="python">

seconds = return self.time_to_secsum_times() + t2.time_to_sec() return sec_to_time(seconds)