问Python使用numpy数组类型追加class属性

EN

class class_1():
    def __init__(self):
        self.x = np.array([0, 0])

    def update(self):
        self.x += 1
        return self.x

cl_1 = class_1()
a = []
for i in range(3):
    y = cl_1.update()
    print(y)
    a.append(y)
print(a)  
# output:
[1 1]
[2 2]
[3 3]
[array([3, 3]), array([3, 3]), array([3, 3])]

class class_2():
    def __init__(self):
        self.x = 0

    def update(self):
        self.x += 1
        return self.x

cl_2 = class_2()
a = []
for i in range(3):
    y = cl_2.update()
    print(y)
    a.append(y)
print(a)
#output
1
2
3
[1, 2, 3]