{
  "id": 586314,
  "title": "Duplicate ranks found in one or more groups.",
  "url": "/competitions/aeroclub-recsys-2025/discussion/586314",
  "author_name": "",
  "post_date": "2025-06-26T05:37:38.707649700Z",
  "votes": 2,
  "comment_count": 2,
  "views": 0,
  "content": "<p>Even though I used this feature to ensure there were no duplicates before submitting, I still got a submission error saying \"Duplicate ranks found in one or more groups.\" I wonder what could be wrong.</p>\n<p><a href=\"https://www.kaggle.com/code/stpeteishii/flightrank-lgbm-ranker\" target=\"_blank\">https://www.kaggle.com/code/stpeteishii/flightrank-lgbm-ranker</a></p>\n<pre><code> ():\n    problems = []\n     ranker_id  df[].unique():\n        group = df[df[] == ranker_id]\n        selected_counts = group[].value_counts()\n        duplicates = selected_counts[selected_counts &gt; ]\n          duplicates.empty:\n            problems.append({\n                : ranker_id,\n                : duplicates.index.tolist(),\n                : duplicates.values.tolist()\n            })\n     problems\n</code></pre>",
  "messages": [
    {
      "id": "3232712",
      "postDate": "06/26/2025 05:37:38",
      "content": "<p>Even though I used this feature to ensure there were no duplicates before submitting, I still got a submission error saying \"Duplicate ranks found in one or more groups.\" I wonder what could be wrong.</p>\n<p><a href=\"https://www.kaggle.com/code/stpeteishii/flightrank-lgbm-ranker\" target=\"_blank\">https://www.kaggle.com/code/stpeteishii/flightrank-lgbm-ranker</a></p>\n<pre><code> ():\n    problems = []\n     ranker_id  df[].unique():\n        group = df[df[] == ranker_id]\n        selected_counts = group[].value_counts()\n        duplicates = selected_counts[selected_counts &gt; ]\n          duplicates.empty:\n            problems.append({\n                : ranker_id,\n                : duplicates.index.tolist(),\n                : duplicates.values.tolist()\n            })\n     problems\n</code></pre>",
      "rawMarkdown": "Even though I used this feature to ensure there were no duplicates before submitting, I still got a submission error saying \"Duplicate ranks found in one or more groups.\" I wonder what could be wrong.\n\nhttps://www.kaggle.com/code/stpeteishii/flightrank-lgbm-ranker\n\n```python\ndef check_duplicate_ranks(df):\n    problems = []\n    for ranker_id in df['ranker_id'].unique():\n        group = df[df['ranker_id'] == ranker_id]\n        selected_counts = group['selected'].value_counts()\n        duplicates = selected_counts[selected_counts > 1]\n        if not duplicates.empty:\n            problems.append({\n                'ranker_id': ranker_id,\n                'duplicate_ranks': duplicates.index.tolist(),\n                'counts': duplicates.values.tolist()\n            })\n    return problems\n```",
      "votes": null
    },
    {
      "id": "3232802",
      "postDate": "06/26/2025 08:25:09",
      "content": "<pre><code>has_duplicates = (\n        submission.groupby()[]\n        .apply( x: x.duplicated().())\n    )\n     has_duplicates.():\n         ParticipantVisibleError()\n</code></pre>\n<p><strong>No duplicate ranks</strong>: Each row within a ranker_id group must have a unique rank</p>",
      "rawMarkdown": "```python\nhas_duplicates = (\n        submission.groupby('ranker_id')['selected']\n        .apply(lambda x: x.duplicated().any())\n    )\n    if has_duplicates.any():\n        raise ParticipantVisibleError(\"Duplicate ranks found in one or more groups\")\n```\n**No duplicate ranks**: Each row within a ranker_id group must have a unique rank",
      "votes": null
    },
    {
      "id": "3234812",
      "postDate": "06/28/2025 11:05:17",
      "content": "<p>you can try to add small random noise(e-7) to scores</p>",
      "rawMarkdown": "you can try to add small random noise(e-7) to scores",
      "votes": null
    }
  ],
  "comments": [
    {
      "id": 3232802,
      "author_name": "samvelkoch",
      "author_url": "",
      "post_date": "06/26/2025 08:25:09",
      "content": "<pre><code>has_duplicates = (\n        submission.groupby()[]\n        .apply( x: x.duplicated().())\n    )\n     has_duplicates.():\n         ParticipantVisibleError()\n</code></pre>\n<p><strong>No duplicate ranks</strong>: Each row within a ranker_id group must have a unique rank</p>",
      "votes": null,
      "replies": []
    },
    {
      "id": 3234812,
      "author_name": "insuperabile",
      "author_url": "",
      "post_date": "06/28/2025 11:05:17",
      "content": "<p>you can try to add small random noise(e-7) to scores</p>",
      "votes": null,
      "replies": []
    }
  ],
  "raw_markdown_by_id": {
    "3232712": "Even though I used this feature to ensure there were no duplicates before submitting, I still got a submission error saying \"Duplicate ranks found in one or more groups.\" I wonder what could be wrong.\n\nhttps://www.kaggle.com/code/stpeteishii/flightrank-lgbm-ranker\n\n```python\ndef check_duplicate_ranks(df):\n    problems = []\n    for ranker_id in df['ranker_id'].unique():\n        group = df[df['ranker_id'] == ranker_id]\n        selected_counts = group['selected'].value_counts()\n        duplicates = selected_counts[selected_counts > 1]\n        if not duplicates.empty:\n            problems.append({\n                'ranker_id': ranker_id,\n                'duplicate_ranks': duplicates.index.tolist(),\n                'counts': duplicates.values.tolist()\n            })\n    return problems\n```",
    "3232802": "```python\nhas_duplicates = (\n        submission.groupby('ranker_id')['selected']\n        .apply(lambda x: x.duplicated().any())\n    )\n    if has_duplicates.any():\n        raise ParticipantVisibleError(\"Duplicate ranks found in one or more groups\")\n```\n**No duplicate ranks**: Each row within a ranker_id group must have a unique rank",
    "3234812": "you can try to add small random noise(e-7) to scores"
  },
  "source": "meta"
}