如何创建一个函数来输出一个类的不同实例的'x‘数量？

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

def count_x_instances(instances):
    count = 0
    for instance in instances:
        if hasattr(instance, 'x'):
            count += 1
    return count

# 创建类的实例
instance1 = MyClass(10)
instance2 = MyClass(20)
instance3 = MyClass(30)

# 创建实例列表
instances = [instance1, instance2, instance3]

# 调用count_x_instances函数并输出结果
print(count_x_instances(instances))