hasattr()函数
hasattr()函数用于判断是否包含对应的属性
语法：
hasattr(object,name)
参数：
object--对象
name--字符串，属性名
返回值：
如果对象有该属性返回True，否则返回False
示例：
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class People: country='China' def __init__(self,name): self.name=name def people_info(self): print('%s is xxx' %(self.name))obj=People('aaa')print(hasattr(People,'country'))#返回值：Trueprint('country' in People.__dict__)#返回值：Trueprint(hasattr(obj,'people_info'))#返回值：Trueprint(People.__dict__)##{'__module__': '__main__', 'country': 'China', '__init__': <function People.__init__ at 0x1006d5620>, 'people_info': <function People.people_info at 0x10205d1e0>, '__dict__': <attribute '__dict__' of 'People' objects>, '__weakref__': <attribute '__weakref__' of 'People' objects>, '__doc__': None} |
getattr()函数
描述：
getattr()函数用于返回一个对象属性值
语法：
getattr(object,name,default)
参数：
object--对象
name--字符串，对象属性
default--默认返回值，如果不提供该参数，在没有对于属性时，将触发AttributeError。
返回值：
返回对象属性值
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class People: country='China' def __init__(self,name): self.name=name def people_info(self): print('%s is xxx' %(self.name))obj=getattr(People,'country')print(obj)#返回值China#obj=getattr(People,'countryaaaaaa')#print(obj)#报错# File "/getattr()函数.py", line 32, in <module># obj=getattr(People,'countryaaaaaa')# AttributeError: type object 'People' has no attribute 'countryaaaaaa'obj=getattr(People,'countryaaaaaa',None)print(obj)#返回值None |
setattr()函数
描述：
setattr函数，用于设置属性值，该属性必须存在
语法：
setattr(object,name,value)
参数：
object--对象
name--字符串，对象属性
value--属性值
返回值：
无
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class People: country='China' def __init__(self,name): self.name=name def people_info(self): print('%s is xxx' %(self.name))obj=People('aaa')setattr(People,'x',111) #等同于People.x=111print(People.x)#obj.age=18setattr(obj,'age',18)print(obj.__dict__)#{'name': 'aaa', 'age': 18}print(People.__dict__)#{'__module__': '__main__', 'country': 'China', '__init__': <function People.__init__ at 0x1007d5620>, 'people_info': <function People.people_info at 0x10215d1e0>, '__dict__': <attribute '__dict__' of 'People' objects>, '__weakref__': <attribute '__weakref__' of 'People' objects>, '__doc__': None, 'x': 111} |
delattr()函数
描述：
delattr函数用于删除属性
delattr(x,'foobar)相当于del x.foobar
语法：
setattr(object,name)
参数：
object--对象
name--必须是对象的属性
返回值：
无
示例：
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class People: country='China' def __init__(self,name): self.name=name def people_info(self): print('%s is xxx' %(self.name))delattr(People,'country') #等同于del People.countryprint(People.__dict__){'__module__': '__main__', '__init__': <function People.__init__ at 0x1006d5620>, 'people_info': <function People.people_info at 0x10073d1e0>, '__dict__': <attribute '__dict__' of 'People' objects>, '__weakref__': <attribute '__weakref__' of 'People' objects>, '__doc__': None} |
补充示例：
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class Foo: def run(self): while True: cmd=input('cmd>>: ').strip() if hasattr(self,cmd): func=getattr(self,cmd) func() def download(self): print('download....') def upload(self): print('upload...')# obj=Foo()# obj.run() |
总结
以上所述是小编给大家介绍的详解Python3 中hasattr()、getattr()、setattr()、delattr()函数，希望对大家有所帮助，如果大家有任何疑问请给我留言，小编会及时回复大家的。在此也非常感谢大家对服务器之家网站的支持！
原文链接：http://www.cnblogs.com/zzzhfo/p/8871661.html
