Adding an attack function for enemy

The below code works completely fine as you will see our Hero has an attack function but when I try to apply the same logic to create an attack function for enemy(jake) it gives me an error Stating int attribute has no object health and I know this cause I defined our hero(mark) as 0 initially to skip check but how do I define it otherwise and fix this

class Hero():
def init(self,name,enemy): = name #hero name = 100 #hero health
self.damage = 20 #hero damage
self.enemy = enemy
print “I”,,"have health : ",
def attack (self,enemy): = - self.damage #20 is the Hero damage value

def checking(self):
    print "I still have health : ",,"I ",,"the great!"

class Enemy():
def init(self,name,hero):
self.damage = 10 #enemy damage = name #enemy name = 100 #enemy health
self.hero = hero
print "I ",,"have health : ",

def checking(self):
    print "I still have health : ",,"I ",,"the great!"

mark = 0 #to define something for mark to prevent error
jake = Enemy(“Jake”,mark) # Jake is our enemy
mark= Hero(“Mark”,jake) # mark is our hero
mark.attack(jake) # mark attacks jake
jake.checking() # checking jake health
mark.checking() # checking mark health