本篇文章给大家带来的内容是关于Python中hasattr(),getattr(),setattr()的用法介绍（代码示例），有一定的参考价值，有需要的朋友可以参考一下，希望对你有所帮助。
1、hasattr(object, name)
判断object里是否有name属性，有就返回True，没有则返回False。
class MyClass(object): name = 'jack' age = '22' obj = MyClass() print(hasattr(obj, 'name')) # True print(hasattr(MyClass, 'age')) # True print(hasattr(obj, 'gender')) # False
2. getattr(object, name, [default])
用来获取object的属性或方法,有就打印出来. 没有就打印默认值,若是没有设置默认值则报错
class MyClass(object):
name = 'jack'
age = '22'
def func(self):
return 'hello world!!!'
obj = MyClass()
print(getattr(MyClass, 'name')) # jack
print(getattr(obj, 'age')) # 22
print(getattr(MyClass, 'func')) # <function MyClass.func at 0x000001ACDE9A9AE8>
print(getattr(obj, 'func')) # <bound method MyClass.func of <__main__.MyClass object at 0x000001D1505D01D0>>
# print(getattr(MyClass, 'func1')) # 没有设置默认值,找不到方法会报错: AttributeError: type object 'MyClass' has no attribute 'func1'
print(getattr(MyClass, 'func1', None)) # 设置了默认值None,找不到就会返回默认值: None
print(getattr(MyClass, 'func')('self')) # hello world!!!
print(getattr(obj, 'func')()) # hello world!!!3. setattr(object, key, value)
用来对object的属性key赋值value. 若是key存在,则更新value的值. 若key不存在,则先创建属性key再对其赋值value.
class MyClass(object): name = 'jack' age = '22' obj = MyClass() setattr(MyClass, 'name', 'tom') print(getattr(MyClass, 'name')) # tom setattr(obj, 'age', 28) print(getattr(obj, 'age')) # 28 setattr(MyClass, 'gender', 'male') print(getattr(MyClass, 'gender')) # male print(getattr(obj, 'gender')) # male setattr(obj, 'hobby', 'skating') print(obj, 'hobby') # <__main__.MyClass object at 0x00000209F5070630> hobby print(MyClass, 'hobby') # <class '__main__.MyClass'> hobby
三个方法一起用:
class MyClass(object): name = 'jack' age = '22' # 判断Myclass是否有gender属性,有则打印,没有则添加 def if_attr(gender='male'): if hasattr(MyClass, 'gender'): return getattr(MyClass, 'gender') return setattr(MyClass, 'gender', gender) if_attr(gender='female') print(getattr(MyClass, 'gender')) # female
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