Python TypeError：“ str”对象不可用于类 [英] Python TypeError: 'str' object is not callable for class

问题描述

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。

Please help me understand this. I created a really simple program to try to understand classes.

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 和其他类似的Stackoverflow问题，但我不明白。非常感谢。

Why does calling the method on the class instance Polly not work? I'm pretty lost. I've looked at http://mail.python.org/pipermail/tutor/2003-May/022128.html and other Stackoverflow questions similiar to this, but I'm not getting it. Thank you so much.

推荐答案

类 Two 有一个实例方法 name（）。因此 Two.name 引用此方法，以下代码可以正常工作：

The class Two has an instance method name(). So Two.name refers to this method and the following code works fine:

Polly = Two()
Two.name(Polly)

但是在 __ init __（），通过将 name 设置为字符串来覆盖它，因此无论何时创建<$ c的新实例$ c>两个， name 属性将引用字符串而不是函数。这就是为什么以下操作失败的原因：

However in __init__(), you override name by setting it to a string, so any time you create a new instance of Two, the name attribute will refer to the string instead of the function. This is why the following fails:

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

只要确保您是为方法和实例变量使用单独的变量名。

Just make sure you are using separate variable names for your methods and your instance variables.

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