40 lines
1.2 KiB
Python
40 lines
1.2 KiB
Python
from __future__ import annotations
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from itertools import chain
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from typing import TYPE_CHECKING
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from narwhals._duckdb.utils import join_column_names
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from narwhals._sql.group_by import SQLGroupBy
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if TYPE_CHECKING:
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from collections.abc import Sequence
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from duckdb import Expression # noqa: F401
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from narwhals._duckdb.dataframe import DuckDBLazyFrame
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from narwhals._duckdb.expr import DuckDBExpr
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class DuckDBGroupBy(SQLGroupBy["DuckDBLazyFrame", "DuckDBExpr", "Expression"]):
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def __init__(
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self,
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df: DuckDBLazyFrame,
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keys: Sequence[DuckDBExpr] | Sequence[str],
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/,
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*,
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drop_null_keys: bool,
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) -> None:
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frame, self._keys, self._output_key_names = self._parse_keys(df, keys=keys)
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self._compliant_frame = frame.drop_nulls(self._keys) if drop_null_keys else frame
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def agg(self, *exprs: DuckDBExpr) -> DuckDBLazyFrame:
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agg_columns = tuple(self._evaluate_exprs(exprs))
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result = self.compliant.native.aggregate(
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tuple(chain(self._keys, agg_columns)), # type: ignore[arg-type]
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join_column_names(*self._keys),
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)
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return self.compliant._with_native(result).rename(
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dict(zip(self._keys, self._output_key_names))
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)
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