Python advanced programming for objects--using @property

1.1   Use@property

When you enter your score score , you need to check this parameter.

>>> class Student (object):

... def get_score (self):

... return Self.__score

... def set_score (self, value):

... if not isinstance (value, int):

... raise ValueError (' score must beinteger ')

... if value < 0 or value > 100:

... raise ValueError (' score Mustbetween 0 and 100. ')

... self.__score = value

...

>>> s = Student ()

>>> S.set_score (60)

>>> S.get_score ()

60

>>> S.set_score (999)

Traceback (most recent):

File "<stdin>", line 1, in <module>

File "<stdin>", line 8, in Set_score

Valueerror:score must between 0 and 100.

Is there any way to access and modify the variables of a class in such an easy manner as to check parameters and use similar properties?

Python's built-in @property Decorator is responsible for turning a method into a property.

>>> class Student (object):

... @property

... def score(self):--score can be understood as a property

... return self.__score-- return property

... @score. Setter

... def score(self, value):--score can be understood as a property

... if not isinstance (value, int):

... raise ValueError (' score must be aninteger. ')

... if value < 0 or value > 100:

... raise ValueError (' score Mustbetween 0 and 100. ')

... self.__score = value-- Modify Properties

...

>>> s = Student ()

>>> S.score =-- Modify the attribute, here is no longer the calling method, thescore property is readable and writable

>>> S.score

60

>>> S.score =-1

Traceback (most recent):

File "<stdin>", line 1, in <module>

File "<stdin>", line ten, in score

Valueerror:score must between 0 and 100.

define read -only properties -Define getter methods only, do not define setter is read-only

>>> class Student (object):

... @property

... def birth (self):

... return Self._birth

... @birth. Setter

... def birth (self, value):

... Self._birth = value--birth readable writable

... @property

... def age (self):

... return 2016-self._birth--age Read Only

...

>>> s = Student ()

>>> S.birth = 1992

>>> S.birth

1992

>>> S.age

24

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Python advanced programming for objects--using @property