38 lines
1 KiB
Python
38 lines
1 KiB
Python
from __future__ import annotations
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from typing import Generic
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from narwhals.typing import SeriesT
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class SeriesListNamespace(Generic[SeriesT]):
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def __init__(self, series: SeriesT) -> None:
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self._narwhals_series = series
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def len(self) -> SeriesT:
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"""Return the number of elements in each list.
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Null values count towards the total.
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Returns:
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A new series.
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Examples:
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>>> import pyarrow as pa
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>>> import narwhals as nw
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>>> s_native = pa.chunked_array([[[1, 2], [3, 4, None], None, []]])
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>>> s = nw.from_native(s_native, series_only=True)
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>>> s.list.len().to_native() # doctest: +ELLIPSIS
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<pyarrow.lib.ChunkedArray object at ...>
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[
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[
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2,
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3,
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null,
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0
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]
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]
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"""
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return self._narwhals_series._with_compliant(
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self._narwhals_series._compliant_series.list.len()
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)
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