93 lines
1.9 KiB
Python
93 lines
1.9 KiB
Python
#!/usr/bin/env python
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# -*- encoding: utf-8 -*-
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"""
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Topic: 扩展property的功能
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Desc :
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"""
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class Person:
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def __init__(self, name):
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self.name = name
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# Getter function
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@property
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def name(self):
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return self._name
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# Setter function
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@name.setter
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def 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._name = value
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# Deleter function
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@name.deleter
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def name(self):
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raise AttributeError("Can't delete attribute")
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class SubPerson(Person):
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@property
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def name(self):
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print('Getting name')
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return super().name
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@name.setter
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def name(self, value):
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print('Setting name to', value)
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super(SubPerson, SubPerson).name.__set__(self, value)
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@name.deleter
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def name(self):
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print('Deleting name')
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super(SubPerson, SubPerson).name.__delete__(self)
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s = SubPerson('Guido')
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print(s.name)
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s.name = 'Larry'
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# A descriptor
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class String:
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def __init__(self, name):
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self.name = name
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def __get__(self, instance, cls):
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if instance is None:
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return self
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return instance.__dict__[self.name]
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def __set__(self, instance, value):
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if not isinstance(value, str):
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raise TypeError('Expected a string')
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instance.__dict__[self.name] = value
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# A class with a descriptor
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class Person:
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name = String('name')
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def __init__(self, name):
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self.name = name
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# Extending a descriptor with a property
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class SubPerson(Person):
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@property
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def name(self):
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print('Getting name')
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return super().name
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@name.setter
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def name(self, value):
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print('Setting name to', value)
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super(SubPerson, SubPerson).name.__set__(self, value)
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@name.deleter
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def name(self):
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print('Deleting name')
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super(SubPerson, SubPerson).name.__delete__(self)
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