rock_paper_scissor_selection.py

class Selection():
    
    OPTIONS = ('paper', 'scissor', 'rock')
    
    def __init__(self, selection):
        if selection not in self.OPTIONS:
            raise ValueError('selection must be one of {}.'.format(', '.join(self.OPTIONS)))
            
        self.selection = selection
        
    def __eq__(self, other):
        """
        The == operator.
        
        Two selections are equal if their selections are equal.
        """
        return self.selection == other.selection
    
    def __ne__(self, other):
        """
        The != operator.
        
        That's simply the opposite of the == operator.
        """
        return not self.__eq__(other)
    
    def __gt__(self, other):
        """
        The > operator.
        
        We'll implement the actual game logic here.
        """
        if self.selection == 'paper':
            return True if other.selection == 'rock' else False
        if self.selection == 'scissor':
            return True if other.selection == 'paper' else False
        if self.selection == 'rock':
            return True if other.selection == 'scissor' else False
            
    def __ge__(self, other):
        """
        The >= operator.
        
        From now on we are building up on the __ge__ and __eq__ operator.
        """
        return self.__gt__(other) or self.__eq__(other)
    
    def __lt__(self, other):
        """
        The < operator.
        """
        return not self.__ge__(other)
    
    def __le__(self, other):
        """
        The <= operator.
        """
        return self.__lt__(other) or self.__eq__(other)
    
    def __str__(self):
        """
        Here's another cool magic function. It defines what's returned 
        when something is calling the str() method on our class. 
        Since it's mainly a wrapper for a string, let's return that 
        string instead of the not-that-descriptive class-instance-version.
        
        Hint: The .format() method is calling str() on all passed values.
        """
        return self.selection