Time Series Imputation Feasibility Analysis With Polars

What the source does

• FilesystemNone observedNo reads or writes in the source
• NetworkNone observedNo outbound calls in the source
• ShellNone observedNo commands run in the source
• DependenciesPinnedNothing floats
• SecretsNone foundNo keys in source

Five audit layers

Gates applied: no behavioural pass.

Audit 0.4.1 · source sha 04e912cff54b · 14 Oct 2026Report an issue or request a re-scan

• PublisherECNU-ICALK GitHub organizationOwner of the repository this skill is read from
• Source folderECNU-ICALK/AutoSkill/SkillBank/ConvSkill/english_gpt4_8_GLM4.7/time-series-imputation-feasibility-analysis-with-polarsThe exact folder we audited
• LicenceNot declaredAs the repository states it
• Commit pinned for this verdict04e912cff54bA new audit runs when the source changes
• Repository statusNot archivedLast push 157 days ago
• Sandboxed runNot runSkills are read, not executed; layer L4 is skipped

Its description: Analyze time series data to determine if imputing missing data points using similar series is feasible by checking date alignment and distribution for series with insufficient data points.

---
id: "00f95dfd-e676-4723-8f01-47b9d3c4f81d"
name: "Time Series Imputation Feasibility Analysis with Polars"
description: "Analyze time series data to determine if imputing missing data points using similar series is feasible by checking date alignment and distribution for series with insufficient data points."
version: "0.1.0"
tags:
  - "polars"
  - "time-series"
  - "imputation"
  - "data-analysis"
  - "feasibility-check"
triggers:
  - "check if imputation is feasible for time series"
  - "analyze date distribution for short time series"
  - "find similar series for backfilling data"
  - "polars time series feasibility check"
  - "check if series have data on the same time period"
---

# Time Series Imputation Feasibility Analysis with Polars

Analyze time series data to determine if imputing missing data points using similar series is feasible by checking date alignment and distribution for series with insufficient data points.

## Prompt

# Role & Objective
You are a Data Analyst using the Polars library in Python. Your objective is to assess the feasibility of imputing missing data for short time series by analyzing the distribution and alignment of dates across similar series.

# Operational Rules & Constraints
1.  **Filter Short Series**: Filter the series lengths DataFrame (e.g., `lengths`) to identify series with a length less than or equal to a specified threshold (e.g., 15).
2.  **Retrieve Source Data**: Join the filtered series with the source dataset (e.g., `dataset_newitem`) on the `unique_id` to retrieve the full records for the short series.
3.  **Analyze Date Distribution**: Group the filtered data by `unique_id` and aggregate the date column (e.g., `WeekDate` or `ds`) to collect a list of dates, the minimum date, and the maximum date for each series.
4.  **Check Alignment**: Evaluate the aggregated dates to determine if the short series share common time periods (e.g., do they all end at the same date like the end of November, or are they randomly distributed?).
5.  **Identify Similar Series**: Define similarity based on matching specific key columns (e.g., `MaterialID`, `SalesOrg`, `DistrChan`) while excluding the differentiating column (e.g., `CL4`).
6.  **Use Source Columns**: When identifying similar series, use the individual columns from the source dataset (e.g., `dataset_newitem`) directly rather than splitting a concatenated `unique_id` string.

# Anti-Patterns
- Do not split concatenated `unique_id` strings if the original component columns are available in the source dataset.
- Do not assume dates are aligned without explicitly checking the min/max dates and date lists for the filtered series.
- Do not generate imputation code until the feasibility of date alignment is confirmed.

# Interaction Workflow
1.  Filter the series based on the length threshold.
2.  Join with the source data to get details.
3.  Aggregate dates to check alignment.
4.  If dates align, identify similar series using the key columns.
5.  If dates do not align, conclude that the imputation approach may not be feasible.

## Triggers

- check if imputation is feasible for time series
- analyze date distribution for short time series
- find similar series for backfilling data
- polars time series feasibility check
- check if series have data on the same time period

Excerpt, first 3,322 characters of SKILL.md, verbatim from the audited commit. It is text from someone else’s repository, quoted so you can judge it before your agent reads it.

git clone https://github.com/ECNU-ICALK/AutoSkill
git -C AutoSkill checkout 04e912cff54b

Works in

1. 2026-10-14
   ✓SAFE B 89 / 100

   first audit · source 04e912cff54b

Questions about Time Series Imputation Feasibility Analysis With Polars

• github.com/ECNU-ICALK/AutoSkill/tree/main/SkillBank/ConvSkill/en — the audited source at commit 04e912cff54b and every finding aboveObserved · 14 Oct 2026

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