Error: unbound method Dragon( ) must be called with Enemy instance as first argument (got Player instance instead)

问题

class Character: 
    def __init__(self):
        self.name = ""
        self.health = 1
        self.health_max = 1

class Player(Character):
    def __init__(self):
        Character.__init__(self)
        self.state = 'normal'
        self.health = 10
        self.health_max = 10

class Monster(Character):
    def Dragon(self):
        self.name = "Dragon"
        self.health = 20

    def Goblin(self):
        name = "Goblin"
        health = 5

p = Player()
p.name = raw_input("Please enter your name: ")
print p.name
print p.state
print p.health
print p.health_max

m = Monster()
enemy = m.Dragon
print enemy.name
print enemy.health

Sorry, I've made this a little simpler to explain what I'm having difficulty with. I'm having a little bit of trouble with the basics of OOP, and I'm running into an issue with this snippet of code. I'm trying to create a "Dragon" here but I'm running into the following error:

Traceback (most recent call last): File "test2.py", line 32, in print enemy.name AttributeError: 'function' object has no attribute 'name'

Can you tell me what I'm doing wrong here? Thanks.

回答1:

You have to create an instance of a class first before you call any functions from it:

myenemy = Enemy()
myenemy.Dragon()

In your code, it looks like you created self.enemy, but later you call self.enemy = Enemy.Dragon(self). Instead of this last line, put self.enemy = self.enemy.Dragon(self).

It seems to be a recurring issue in the rest of your code as well. Commands = {'explore': Player.explore} should probably be Commands = {'explore': p.explore} (after you have created the instance p).

---

Since your updated code, I think you're getting functions and classes mixed up. Dragon is a function, and when you do enemy = m.Dragon, you are simply copying the function onto enemy. And thus when you do enemy.name, thinking it's a class, an error is raised, because enemy is now a function, not an instance.

You will have to create separate classes for different monsters:

class Dragon:
    self.name = "Dragon"
    self.health = 20

class Goblin:
    name = "Goblin"
    health = 5

来源：https://stackoverflow.com/questions/17437837/error-unbound-method-dragon-must-be-called-with-enemy-instance-as-first-argu