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py-07-pandas-top-n

0.429
3/7 tests· lib-knowledge

Proposed solution

```python
import pandas as pd

def top_n_per_group(df: pd.DataFrame, group_col: str, value_col: str, n: int) -> pd.DataFrame:
    # Group by the specified column, sort within each group by the value column in descending order
    # and limit the number of rows to n. Then, reset the index to get a clean RangeIndex.
    result = df.groupby(group_col, group_keys=False).apply(
        lambda x: x.sort_values(value_col, ascending=False).head(n)
    ).reset_index(drop=True)
    
    return result
```

Test output (stdout)

ibs/index.pyx:197: in pandas._libs.index.IndexEngine.get_loc
    ???
pandas/_libs/hashtable_class_helper.pxi:7668: in pandas._libs.hashtable.PyObjectHashTable.get_item
    ???
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

>   ???
E   KeyError: 'g'

pandas/_libs/hashtable_class_helper.pxi:7676: KeyError

The above exception was the direct cause of the following exception:

    def test_group_order_follows_first_appearance():
        df = pd.DataFrame({
            "g": ["z", "a", "z", "a"],
            "v": [1, 2, 3, 4],
        })
        out = top_n_per_group(df, "g", "v", 1)
        # "z" appears first, so it should come first
>       assert list(out["g"]) == ["z", "a"]
                    ^^^^^^^^

test_top_n.py:61: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
/home/psc/miniconda3/lib/python3.12/site-packages/pandas/core/frame.py:4378: in __getitem__
    indexer = self.columns.get_loc(key)
              ^^^^^^^^^^^^^^^^^^^^^^^^^
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

self = Index(['v'], dtype='str'), key = 'g'

    def get_loc(self, key):
        """
        Get integer location, slice or boolean mask for requested label.
    
        Parameters
        ----------
        key : label
            The key to check its location if it is present in the index.
    
        Returns
        -------
        int if unique index, slice if monotonic index, else mask
            Integer location, slice or boolean mask.
    
        See Also
        --------
        Index.get_slice_bound : Calculate slice bound that corresponds to
            given label.
        Index.get_indexer : Computes indexer and mask for new index given
            the current index.
        Index.get_non_unique : Returns indexer and masks for new index given
            the current index.
        Index.get_indexer_for : Returns an indexer even when non-unique.
    
        Examples
        --------
        >>> unique_index = pd.Index(list("abc"))
        >>> unique_index.get_loc("b")
        1
    
        >>> monotonic_index = pd.Index(list("abbc"))
        >>> monotonic_index.get_loc("b")
        slice(1, 3, None)
    
        >>> non_monotonic_index = pd.Index(list("abcb"))
        >>> non_monotonic_index.get_loc("b")
        array([False,  True, False,  True])
        """
        casted_key = self._maybe_cast_indexer(key)
        try:
            return self._engine.get_loc(casted_key)
        except KeyError as err:
            if isinstance(casted_key, slice) or (
                isinstance(casted_key, abc.Iterable)
                and any(isinstance(x, slice) for x in casted_key)
            ):
                raise InvalidIndexError(key) from err
>           raise KeyError(key) from err
E           KeyError: 'g'

/home/psc/miniconda3/lib/python3.12/site-packages/pandas/core/indexes/base.py:3648: KeyError
_________________________ test_preserves_extra_columns _________________________

    def test_preserves_extra_columns():
        df = pd.DataFrame({
            "team": ["a", "a", "b"],
            "score": [1, 2, 3],
            "extra": ["p", "q", "r"],
        })
        out = top_n_per_group(df, "team", "score", 1)
>       assert list(out.columns) == ["team", "score", "extra"]
E       AssertionError: assert ['score', 'extra'] == ['team', 'score', 'extra']
E         
E         At index 0 diff: 'score' != 'team'
E         Right contains one more item: 'extra'
E         Use -v to get more diff

test_top_n.py:72: AssertionError
=========================== short test summary info ============================
FAILED test_top_n.py::test_basic_top2 - AssertionError: assert ['name', 'scor...
FAILED test_top_n.py::test_group_smaller_than_n - KeyError: 'team'
FAILED test_top_n.py::test_group_order_follows_first_appearance - KeyError: 'g'
FAILED test_top_n.py::test_preserves_extra_columns - AssertionError: assert [...
4 failed, 3 passed in 0.28s
Self-repair attempts
[
  {
    "total": 7,
    "answer": "```python\nimport pandas as pd\n\ndef top_n_per_group(df: pd.DataFrame, group_col: str, value_col: str, n: int) -> pd.DataFrame:\n    # Group by the specified column, sort within each group by the value column in descending order\n    # and limit the number of rows to n. Then, reset the index to get a clean RangeIndex.\n    result = df.groupby(group_col, group_keys=False).apply(\n        lambda x: x.sort_values(value_col, ascending=False).head(n)\n    ).reset_index(drop=True)\n    \n    return result\n```",
    "passed": 3,
    "test_error": "          Integer location, slice or boolean mask.\n    \n        See Also\n        --------\n        Index.get_slice_bound : Calculate slice bound that corresponds to\n            given label.\n        Index.get_indexer : Computes indexer and mask for new index given\n            the current index.\n        Index.get_non_unique : Returns indexer and masks for new index given\n            the current index.\n        Index.get_indexer_for : Returns an indexer even when non-unique.\n    \n        Examples\n        --------\n        >>> unique_index = pd.Index(list(\"abc\"))\n        >>> unique_index.get_loc(\"b\")\n        1\n    \n        >>> monotonic_index = pd.Index(list(\"abbc\"))\n        >>> monotonic_index.get_loc(\"b\")\n        slice(1, 3, None)\n    \n        >>> non_monotonic_index = pd.Index(list(\"abcb\"))\n        >>> non_monotonic_index.get_loc(\"b\")\n        array([False,  True, False,  True])\n        \"\"\"\n        casted_key = self._maybe_cast_indexer(key)\n        try:\n            return self._engine.get_loc(casted_key)\n        except KeyError as err:\n            if isinstance(casted_key, slice) or (\n                isinstance(casted_key, abc.Iterable)\n                and any(isinstance(x, slice) for x in casted_key)\n            ):\n                raise InvalidIndexError(key) from err\n>           raise KeyError(key) from err\nE           KeyError: 'g'\n\n/home/psc/miniconda3/lib/python3.12/site-packages/pandas/core/indexes/base.py:3648: KeyError\n_________________________ test_preserves_extra_columns _________________________\n\n    def test_preserves_extra_columns():\n        df = pd.DataFrame({\n            \"team\": [\"a\", \"a\", \"b\"],\n            \"score\": [1, 2, 3],\n            \"extra\": [\"p\", \"q\", \"r\"],\n        })\n        out = top_n_per_group(df, \"team\", \"score\", 1)\n>       assert list(out.columns) == [\"team\", \"score\", \"extra\"]\nE       AssertionError: assert ['score', 'extra'] == ['team', 'score', 'extra']\nE         \nE         At index 0 diff: 'score' != 'team'\nE         Right contains one more item: 'extra'\nE         Use -v to get more diff\n\ntest_top_n.py:72: AssertionError\n=========================== short test summary info ============================\nFAILED test_top_n.py::test_basic_top2 - AssertionError: assert ['name', 'scor...\nFAILED test_top_n.py::test_group_smaller_than_n - KeyError: 'team'\nFAILED test_top_n.py::test_group_order_follows_first_appearance - KeyError: 'g'\nFAILED test_top_n.py::test_preserves_extra_columns - AssertionError: assert [...\n4 failed, 3 passed in 0.28s"
  },
  {
    "total": 7,
    "answer": "```python\nimport pandas as pd\n\ndef top_n_per_group(df: pd.DataFrame, group_col: str, value_col: str, n: int) -> pd.DataFrame:\n    # Group by the specified column, sort within each group by the value column in descending order\n    # and limit the number of rows to n. Then, reset the index to get a clean RangeIndex.\n    # Ensure that the result preserves all original columns.\n    result = df.groupby(group_col, as_index=False)[[group_col, value_col]].apply(\n        lambda x: x.sort_values(value_col, ascending=False).head(n)\n    ).reset_index(drop=True)\n    \n    # Add back any extra columns that were not in the groupby columns\n    extra_cols = df.columns.difference([group_col, value_col])\n    result = pd.merge(result, df.loc[:, extra_cols], on=group_col, how='left')\n    \n    return result\n```",
    "passed": 0,
    "test_error": "^^^^^^^^^^^^\n_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ \n\nself =   extra\n0     p\n1     q\n2     r, key = 'team', axis = 0\n\n    @final\n    def _get_label_or_level_values(self, key: Level, axis: AxisInt = 0) -> ArrayLike:\n        \"\"\"\n        Return a 1-D array of values associated with `key`, a label or level\n        from the given `axis`.\n    \n        Retrieval logic:\n          - (axis=0): Return column values if `key` matches a column label.\n            Otherwise return index level values if `key` matches an index\n            level.\n          - (axis=1): Return row values if `key` matches an index label.\n            Otherwise return column level values if 'key' matches a column\n            level\n    \n        Parameters\n        ----------\n        key : Hashable\n            Label or level name.\n        axis : int, default 0\n            Axis that levels are associated with (0 for index, 1 for columns)\n    \n        Returns\n        -------\n        np.ndarray or ExtensionArray\n    \n        Raises\n        ------\n        KeyError\n            if `key` matches neither a label nor a level\n        ValueError\n            if `key` matches multiple labels\n        \"\"\"\n        axis = self._get_axis_number(axis)\n        first_other_axes = next(\n            (ax for ax in range(self._AXIS_LEN) if ax != axis), None\n        )\n    \n        if self._is_label_reference(key, axis=axis):\n            self._check_label_or_level_ambiguity(key, axis=axis)\n            if first_other_axes is None:\n                raise ValueError(\"axis matched all axes\")\n            values = self.xs(key, axis=first_other_axes)._values\n        elif self._is_level_reference(key, axis=axis):\n            values = self.axes[axis].get_level_values(key)._values\n        else:\n>           raise KeyError(key)\nE           KeyError: 'team'\n\n/home/psc/miniconda3/lib/python3.12/site-packages/pandas/core/generic.py:1776: KeyError\n=========================== short test summary info ============================\nFAILED test_top_n.py::test_basic_top2 - KeyError: 'team'\nFAILED test_top_n.py::test_index_is_rangeindex - KeyError: 'team'\nFAILED test_top_n.py::test_group_smaller_than_n - KeyError: 'team'\nFAILED test_top_n.py::test_n_equals_one - KeyError: 'team'\nFAILED test_top_n.py::test_does_not_mutate_input - KeyError: 'team'\nFAILED test_top_n.py::test_group_order_follows_first_appearance - KeyError: 'g'\nFAILED test_top_n.py::test_preserves_extra_columns - KeyError: 'team'\n7 failed in 0.42s"
  },
  {
    "total": 7,
    "answer": "```python\nimport pandas as pd\n\ndef top_n_per_group(df: pd.DataFrame, group_col: str, value_col: str, n: int) -> pd.DataFrame:\n    # Group by the specified column, sort within each group by the value column in descending order\n    # and limit the number of rows to n. Then, reset the index to get a clean RangeIndex.\n    # Ensure that the result preserves all original columns.\n    result = df.groupby(group_col, as_index=False)[[group_col, value_col]].apply(\n        lambda x: x.sort_values(value_col, ascending=False).head(n)\n    ).reset_index(drop=True)\n    \n    # Add back any extra columns that were not in the groupby columns\n    extra_cols = df.columns.difference([group_col, value_col])\n    result = pd.merge(result, df.loc[:, extra_cols], on=group_col, how='left')\n    \n    return result\n```",
    "passed": 0,
    "test_error": ""
  }
]
System prompt
You are an expert programmer. Solve the task exactly as specified. Output your solution as fenced code blocks using the required file name(s) and the exact function/type signatures requested. Prefer correctness; do not include prose outside code unless asked.