Question

出于某种原因,当我围绕财产功能的争论而转变时,它就留下了一个错误。我只想理解为什么。

class Geeks:
    def __init__(self):
        self._age = 0

    # function to get value of _age
    def get_age(self):
        print("getter method called")
        return self._age

    # function to set value of _age
    def set_age(self, a):
        print("setter method called")
        self._age = a

    age = property(get_age, set_age)

mark = Geeks()
mark.age = 10
print(mark.age)

产出:

setter method called
getter method called
10

错误发生时,我转接了<代码> = 财产(植被、定型_age)

class Geeks:
    def __init__(self):
        self._age = 0

    # function to get value of _age
    def get_age(self):
        print("getter method called")
        return self._age

    # function to set value of _age
    def set_age(self, a):
        print("setter method called")
        self._age = a

    age = property(set_age, get_age)

mark = Geeks()
mark.age = 10
print(mark.age)

产出

ERROR!
Traceback (most recent call last):
  File "<string>", line 18, in <module>
TypeError: Geeks.get_age() takes 1 positional argument but 2 were given

Why am I not allowed to switch around the arguments?

Answer 1

在有问题的<条码>property电话中,你有错的机组和跳板。在没有代号参数的情况下,Sharma将坚持要求(沉积)的命令。

如果你重新使用positional参数(并且你是),那么,采集器应当首先使用。既然你挥舞了他们,那么这两个论点都将是错误的,因为<>><>><>>>>>>。依据的事实是:

a getter is a function that takes no arguments (other than self) and returns a value; and
a setter is defined as a function that takes one argument (again, other than self) and returns nothing.

如果你真的想要他们,你需要姓名<>。他们明确表明,斯图尔将适应你的命令:

age = property(fset=set_age, fget=get_age)

但是,你希望考虑的一件事是使用财产校正器,使其更明确地说明为此目的的职能。对您来说,这将带来这样的情况:

@property
def age(self):
    return self._age
    
@age.setter
def age(self, val):
    self._age = val

友情链接