Question

我试图模仿c＃扩展的行为，例如针对Python类，该类暴露了一些包含缓存描述符的属性，这些属性返回各种命名元组的集合。

from collections import namedtuple


class Descriptor:
    def __init__(self, func):
        self.func = func
        self.name = func.__name__
        self.__doc__ = func.__doc__

    def __get__(self, ctx, owner=None):
        if ctx is None:
            return self
        result = self.func(ctx)
        setattr(ctx, self.name, result)
        return result


class Container(tuple):
    def __new__(cls, seq):
        return super().__new__(cls, seq)

    def get(self, **kwargs):
        """Gets an item matching the specified criteria.

        :param dict kwargs: One or more key value pairs of criteria to filter with.
        :returns: The first item matching the given criteria or None.

        """

        for item in self:
            if all(getattr(item, k, None) == v for k, v in kwargs.items()):
                return item

    def where(self, **kwargs):
        """Gets all items matching the specified criteria.

        :param dict kwargs: One or more key value pairs of criteria to filter with.
        :returns: All items matching the given criteria or None.

        """

        return Container((x for x in self if all(getattr(x, k, None) == v for k, v in kwargs.items())))


Item = namedtuple('Item', ('foo', 'bar', 'baz'))


class Class:

    @Descriptor
    def prop(self):
        result = [Item(x, x * 10, x * 100) for x in range(5)]
        return Container(result)


c = Class()
for x in c.prop:
    # Properties of Item are not available to introspection.
    print(x.foo, x.bar)

y = c.prop
# Properties of y (get, where) are not available to introspection.
print(y.get(foo=1))

当迭代c.prop时，应调用基本元组方法，但内省不存在。

暗示Container类的添加方法的问题得到/这个单个类包含各种类型，如本机元组。对于为每个命名元组创建具有适当文档字符串的容器没有用。

我在pycharm和ipython中测试。一旦在调用之后对象被实例化，Ipython就会收集一些洞察力，但这还不够。

如何构建促进这一想法的通用容器？

IDE中的Python内省

0 个答案: