'str' object is not callable when trying to set object property

问题

Having such object

class testDec(object):
    def __init__(self):
        self.__x = 'stuff'
    @property
    def x(self):
        print 'called getter'
        return self.__x
    @x.setter
    def x(self, value):
        print 'called setter'
        self.__x = value

Why I can not set attribute __x ? Here is a traceback

>>> a.x
called getter
'stuff'
>>> a.x(11)
called getter
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
TypeError: 'str' object is not callable

I'm using 2.7.6 Python

回答1:

The syntax for properties looks like normal attribute access (by design).

It's the main use case of the property decorator, for creating "managed attributes" precisely so that you don't have to use function call syntax for getters and setters:

• a.x() just becomes a.x
• a.x(11) just becomes a.x = 11

Ergo:

>>> a = testDec()
>>> a.x
called getter
'stuff'
>>> a.x = 123
called setter
>>> a.x
called getter
123

This is all documented here.

Note: usually in python you would store the "unmanaged" attribute as self._x, not self.__x.

来源：https://stackoverflow.com/questions/34299172/str-object-is-not-callable-when-trying-to-set-object-property