86 lines
1.8 KiB
Python
86 lines
1.8 KiB
Python
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#!/usr/bin/env python
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# -*- encoding: utf-8 -*-
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"""
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Topic: 可管理的属性
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Desc :
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"""
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import math
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class Person:
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def __init__(self, first_name):
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self.first_name = first_name
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# Getter function
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@property
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def first_name(self):
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return self._first_name
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# Setter function
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@first_name.setter
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def first_name(self, value):
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if not isinstance(value, str):
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raise TypeError('Expected a string')
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self._first_name = value
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# Deleter function (optional)
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@first_name.deleter
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def first_name(self):
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raise AttributeError("Can't delete attribute")
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a = Person('Guido')
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print(a.first_name) # Calls the getter
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# a.first_name = 42 # Calls the setter
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# del a.first_name # Calls the deleter
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class Person1:
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def __init__(self, first_name):
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self.set_first_name(first_name)
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# Getter function
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def get_first_name(self):
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return self._first_name
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# Setter function
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def set_first_name(self, value):
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if not isinstance(value, str):
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raise TypeError('Expected a string')
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self._first_name = value
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# Deleter function (optional)
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def del_first_name(self):
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raise AttributeError("Can't delete attribute")
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# Make a property from existing get/set methods
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name = property(get_first_name, set_first_name, del_first_name)
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print(Person1.name.fget)
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print(Person1.name.fset)
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print(Person1.name.fdel)
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class Circle:
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"""动态计算的property"""
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def __init__(self, radius):
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self.radius = radius
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@property
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def diameter(self):
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return self.radius ** 2
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@property
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def perimeter(self):
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return 2 * math.pi * self.radius
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@property
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def area(self):
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return math.pi * self.radius ** 2
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c = Circle(4.0)
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print(c.radius)
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print(c.area) # Notice lack of ()
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