hasattr()函數

hasattr()函數用于判斷是否包含對應的屬性

語法：

hasattr(object,name)

參數：

object--對象

name--字符串，屬性名

返回值：

如果對象有該屬性返回True，否則返回False

示例：

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()函數

描述：

getattr()函數用于返回一個對象屬性值

語法：

getattr(object,name,default)

參數：

object--對象

name--字符串，對象屬性

default--默認返回值，如果不提供該參數，在沒有對于屬性時，將觸發AttributeError。

返回值：

返回對象屬性值

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)#報錯# File "/getattr()函數.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()函數

描述：

setattr函數，用于設置屬性值，該屬性必須存在

語法：

setattr(object,name,value)

參數：

object--對象

name--字符串，對象屬性

value--屬性值

返回值：

無

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()函數

描述：

delattr函數用于刪除屬性

delattr(x,'foobar)相當于del x.foobar

語法：

setattr(object,name)

參數：

object--對象

name--必須是對象的屬性

返回值：

無

示例：