Lec19-Attributes

2024-10-20 117 words One minute

Contents

Attributes

class attribute

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class MyClass:
    x = 10
    def __init__(self):
        self.y = 20

print(MyClass.x)  # 10

like static member variables

getattr and hasattr

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class MyClass:
    x = 10
    def __init__(self):
        self.y = 20

print(getattr(MyClass, 'x'))  # 10
print(hasattr(MyClass, 'z'))  # False

assignment to attributes

如果重名，先查看实例的属性

Function calls in class

bound method

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class MyClass:
    def __init__(self, x):
        self.x = x
    def my_method(self):
        print(self.x)

obj = MyClass(10)
obj.my_method # <bound method MyClass.my_method of <__main__.MyClass object at 0x000001E8D7D7D708>>

why bound? because the method is bound to the instance of the class, so it is filled with the self parameter