Maison > Article > développement back-end > Fonctions Hasattr(), getattr(), setattr(), delattr() et exemples de codes en Python3
Cet article présente en détail les fonctions hasattr(), getattr(), setattr() et delattr() dans Python3 à travers un exemple de code. Il est très bon et a une valeur de référence. Les amis qui en ont besoin peuvent s'y référer. 🎜>
hasattr(object,name)
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:True print('country' in People.__dict__) #返回值:True print(hasattr(obj,'people_info')) #返回值:True print(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}
Syntaxe :
getattr(object,name,default)
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(object,name,value)
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=111 print(People.x) #obj.age=18 setattr(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}
Syntaxe :
setattr(object,name)
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.country print(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}
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()
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