Python 类型错误 : 'str' object is not callable for class

Question

请帮助我理解这一点。我创建了一个非常简单的程序来尝试理解类。

class One(object):
    def __init__(self, class2):
        self.name = 'Amy'
        self.age = 21
        self.class2 = class2

    def greeting(self):
        self.name = raw_input("What is your name?: ")
        print 'hi %s' % self.name

    def birthday(self):
        self.age = int(raw_input("What is your age?: "))
        print self.age 

    def buy(self):
        print 'You buy ', self.class2.name

class Two(object):
    def __init__(self): 
        self.name = 'Polly'
        self.gender = 'female'

    def name(self):
        self.gender = raw_input("Is she male or female? ")
        if self.gender == 'male'.lower():
            self.gender = 'male'
        else:
            self.gender = 'female'

        self.name = raw_input("What do you want to name her? ")

        print "Her gender is %s and her name is %s" % (self.gender, self.name)

Polly = Two()
Amy = One(Polly) 
# I want it to print 


Amy.greeting()
Amy.buy() 
Amy.birthday()

问题代码

Polly.name() # TypeError: 'str' object is not callable
Two.name(Polly)# Works. Why?

为什么在类实例 Polly 上调用方法不起作用？我很迷路。我看过 http://mail.python.org/pipermail/tutor/2003-May/022128.html和其他与此类似的 Stackoverflow 问题，但我不明白。太感谢了。

Answer 1

类Two 有一个实例方法name()。所以 Two.name 引用了这个方法，下面的代码工作正常:

Polly = Two()
Two.name(Polly)

但是在 __init__() 中，您可以通过将 name 设置为字符串来覆盖它，因此任何时候您都可以创建 Two 的新实例, name 属性将引用字符串而不是函数。这就是以下失败的原因:

Polly = Two()      # Polly.name is now the string 'Polly'
Polly.name()       # this is equivalent to 'Polly'()

只需确保您为方法和实例变量使用不同的变量名即可。