定义 Python 中类变量的正确方式是什么?
类变量是在__init__方法外部声明的变量。它们是静态元素,这意味着它们属于类而不是类实例。这些类变量由该类的所有实例共享。类变量的示例代码
实例
class MyClass: __item1 = 123 __item2 = "abc" def __init__(self): #pass or something else
通过更多代码,你会有更清晰的了解 −
class MyClass: stat_elem = 456 def __init__(self): self.object_elem = 789 c1 = MyClass() c2 = MyClass() # Initial values of both elements >>> print c1.stat_elem, c1.object_elem 456 789 >>> print c2.stat_elem, c2.object_elem 456 789 # Let's try changing the static element MyClass.static_elem = 888 >>> print c1.stat_elem, c1.object_elem 888 789 >>> print c2.stat_elem, c2.object_elem 888 789 # Now, let's try changing the object element c1.object_elem = 777 >>> print c1.stat_elem, c1.object_elem 888 777 >>> print c2.stat_elem, c2.object_elem 888 789
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