使用相同的键集过滤两个 py2store 存储答案

【问题标题】：Filtering two py2store stores with the same set of keys使用相同的键集过滤两个 py2store 存储
【发布时间】：2020-08-28 18:54:27
【问题描述】：

在下面的代码中，基于我使用py2store 找到的示例，我使用with_key_filt 制作了两个 dacc（一个带有训练数据，另一个带有测试数据）。我确实得到了一个过滤的annots 商店，但wfs 商店没有被过滤。我做错了什么？

from py2store import cached_keys

class Dacc:
    """Waveform and annotation data access"""
    def __init__(self, wfs, annots, annot_to_tag=lambda x: x['tag']):
        self.wfs = wfs  # waveform store  (keys: filepaths, values: numpy arrays)
        self.annots = annots  # annotation store (keys: filepaths, values: dicts or pandas series)
        self.annot_to_tag = annot_to_tag  # function to compute a tag from an annotation item

    @classmethod
    def with_key_filt(cls, key_filt, wfs, annots, annot_to_tag, chunker):
        """
        Make an instance of the dacc class where the data is filtered out.
        You could also filter out externaly, but this can be convenient
        """
        filtered_annots = cached_keys(annots, keys_cache=key_filt)
        return cls(wfs, filtered_annots, annot_to_tag)

    def wf_tag_gen(self):
        """Generator of (wf, tag) tuples"""
        for k in self.annots:
            try:
                wf = self.wfs[k]
                annot = self.annots[k]
                yield wf, self.annot_to_tag(annot)
            except KeyError:
                pass

【问题讨论】：

标签： python key store filtered

【解决方案1】：

似乎with_key_filt 的意图似乎是过滤annots，它本身被用作wg_tag_gen 生成器的种子（可能还有您未发布的其他生成器）。因此，它确实过滤了所有内容。

但我同意您的期望，即 wfs 也应该被过滤。为此，您只需添加一行来过滤wfs。

class TheDaccYouWant(Dacc):
    @classmethod
    def with_key_filt(cls, key_filt, wfs, annots, annot_to_tag, chunker):
        filtered_annots = cached_keys(annots, keys_cache=key_filt)
        wfs = cached_keys(wfs, keys_cache=key_filt)  # here's what was added
        return cls(wfs, filtered_annots, annot_to_tag, chunker)

【讨论】：