Question

假设我要创建一个类，应用一个方法并为结果对象设置一个属性。

arr = np.array([1,2,3])

class Transformer:

    def __init__(self, array):
        self.array = array

    def operator(self):
        operator = (self.array * 2) + 60
        return operator

    @staticmethod
    def meta(array):
        meta = (max(array) + 17)
        return meta

    def to_operator(self):
        op = self.operator()
        meta = self.meta(op)
        setattr(op, 'meta', meta)# or op.meta = meta
        return op


t = Transformer(np.array([1, 2, 3]))
t1 = t.to_operator()
print(t1.meta())

在这里出现以下错误：

AttributeError：“ numpy.ndarray”对象没有属性“ meta”

预期结果：

 >>> 83

Answer 1

运行代码时，出现错误，错误行显示为setattr(op, 'meta', meta)：

Traceback (most recent call last):
  File "/home/ralf/PycharmProjects/scratch_pad/run.py", line 44, in <module>
    t1 = t.to_operator()
  File "/home/ralf/PycharmProjects/scratch_pad/run.py", line 29, in to_operator
    setattr(op, 'meta', meta)
AttributeError: 'numpy.ndarray' object has no attribute 'meta'

在以下相关问题中了解原因：

如何定义类对象的新属性

1 个答案: