Subclasses in Python

[Thomas Philips]

I'm teaching myself programming using Python, and have a question
about subclasses. My game has two classes, Player and Alien, with
identical functions, and I want to make Player a base class and Alien
a derived class. The two classes are described below

class Player(object):
    #Class attributes for class Player
    threshold = 50
    n=0 #n is the number of players

    #Private methods for class Player
    def __init__(self,name):
        self.name = name
        self.strength = 100
        Player.n +=1

    def __del__(self):
        Player.n -=1
        print "You got me, Alien"
    
    #Public methods for class Player
    def blast(self,enemy,energy):
        enemy.hit(energy)

    def hit(self,energy):
        self.strength -= energy
        if(self.strength <= Player.threshold):
            self.__del__()

class Alien(Player):
    #Class attributes for class Alien
    threshold = 100
    n=0 #n is the number of players

    #Private methods for class Alien
    def __init__(self,name):
        self.name = name
        self.strength = 100
        Alien.n +=1

    def __del__(self):
        Alien.n -=1
        print "You got me, earthling"
    
    #Public methods for class Alien
    def hit(self,energy):
        self.strength -= energy
        if(self.strength <= Alien.threshold):
            self.__del__()

The two classes are almost identical, except that:
1. When a new player is instantiated or destroyed, Player.n is
incremented/decremented, while when a new alien is instantiated,
Alien.n is incremented/decremented.
2. When hit by an energy blast, the player and the alien have
different thresholds below which they die.

How can I base the Alien's __init__(), __del__() and hit() methods on
the Player's methods, while ensuring that the appropriate class
variables are incremented/decremented when a new object is
instantiated and that the appropriate threshold is used when the
player/alien is hit by an energy bolt?

Thomas Philips