Comment appeler des méthodes statiques de classe à partir du corps de classe en Python ?-Tutoriel Python-php.cn

Comment appeler des méthodes statiques de classe à partir du corps de classe en Python ?

Patricia Arquette

Libérer： 2024-10-18 06:47:03

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How to Call Class Static Methods from within the Class Body in Python?

Calling Class Staticmethod within the Class Body in Python

For Python versions 3.10 and above, calling a static method from within the class body is straightforward. However, for versions 3.9 and earlier, this poses a challenge.

Error Encountered

When attempting to call a static method from within the class body, you may encounter the following error:

1	`TypeError:` `'staticmethod'` `object is not callable`

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This error occurs because static methods, when declared using the staticmethod decorator, become descriptors. Descriptors bind to the class instead of the instance, making them inaccessible from within the class body.

Workaround Using func Attribute

One workaround is to access the original raw function through the __func__ attribute of the static method object:

<code class="python">class Klass(object):
 
    @staticmethod
    def stat_func():
        return 42
 
    _ANS = stat_func.__func__()  # call the staticmethod
 
    def method(self):
        ret = Klass.stat_func()
        return ret</code>

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Additional Notes

While the above workaround is functional, the __func__ attribute is an implementation detail and may change in future Python versions.
For Python versions 3.10 and above, calling static methods from within the class body is straightforward as shown below:

<code class="python">class Klass(object):
 
    @staticmethod
    def stat_func():
        return 42
 
    def method(self):
        ret = Klass.stat_func()
        return ret</code>