Python 类继承时覆盖类属性的问题

class Base(object):
    PRODUCT = 1

    CLIENT = PRODUCT * 10


class Base1(Base):
    PRODUCT = 2


print(Base.CLIENT)
print(Base1.CLIENT)

请问 Base1 的 CLIENT 要怎么才能变成 20, 不重复写 CLIENT 的表达式情况下