Question

假设我使用的库实现了一个类

class Base(object):
    def __init__(self, private_API_args):
        ...

它意味着只能通过

进行实例化

def factory(public_API_args):
    """
    Returns a Base object
    """
    ...

我想通过添加几个方法来扩展Base类：

class Derived(Base):
    def foo(self):
        ...
    def bar(self):
        ...

是否可以在不调用私有API的情况下初始化Derived？

换句话说，我应该替换factory函数？

Answer 1

如果您无权访问私有API，则可以执行以下操作：

class Base(object):
    def __init__(self, private_API_args):
        ...


def factory(public_API_args):
    """ Returns a Base object """
    # Create base object with all private API methods
    return base_object


class Derived(object):
    def __init__(self, public_API_args):
        # Get indirect access to private API method of the Base object class
        self.base_object = factory(public_API_args)

    def foo(self):
        ...
    def bar(self):
        ...

现在在主脚本中：

#!/usr/bin/python3

# create the derivate object with public API args
derived_object = Derived(public_API_args)

# to call private API methods
derived_object.base_object.method()

# to call your method from the same object
derived_object.foo()
derived_object.bar()

我可以从一个只能由＆＃34;工厂＆＃34;？创建的类中派生出来吗？

1 个答案: