R-7.13 from Algorithms and Data Structure (In Python)

Update the PositionalList class to support an additional method find(e), which returns the position of the (first occurrence of ) element e in the list.

Function find() implemented as a member function of the PositionalList class. It accepts an element e, and return the position of the first occurrence of e in the list. If e is not found in the list, you should return None. Provide test code for call the find() function and print out this position if found and not found if the return value is None.