酸洗 Keras 回归器模型错误：无法酸洗 _thread.RLock 对象

Question

我想腌制一个包含 Keras 回归器和标准缩放器的管道。但我收到以下错误：无法腌制 _thread.RLock 对象。关于可能是什么问题的任何想法？

  {
    $addFields: {
      categories: {
        $reduce: {
          input: "$categories",
          initialValue: { level: -1, presentChild: [], prevChild: [] },
          in: {
            $let: {
              vars: {
                prev: {
                  $cond: [
                    { $eq: ["$$value.level", "$$this.level"] },
                    "$$value.prevChild",
                    "$$value.presentChild"
                  ]
                },
                current: {
                  $cond: [{ $eq: ["$$value.level", "$$this.level"] }, "$$value.presentChild", []]
                }
              },
              in: {
                level: "$$this.level",
                prevChild: "$$prev",
                presentChild: {
                  $concatArrays: [
                    "$$current",
                    [
                      {
                        $mergeObjects: [
                          "$$this",
                          {
                            categories: {
                              $filter: {
                                input: "$$prev",
                                as: "e",
                                cond: { $eq: ["$$e.parent", "$$this.category"] }
                              }
                            }
                          }
                        ]
                      }
                    ]
                  ]
                }
              }
            }
          }
        }
      }
    }
  },
  { $addFields: { categories: "$categories.presentChild" } }
])