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# pandas.Series.struct.field

Series.struct.field(name_or_index)

  Extract a child field of a struct as a Series.

  Parameters:
    name_or_index str | bytes | int | expression | list

      Name or index of the child field to extract.

      For list-like inputs, this will index into a nested struct.

  Returns:
    pandas.Series

      The data corresponding to the selected child field.

  See also

  `Series.struct.explode`

    Return all child fields as a DataFrame.

  Notes

  The name of the resulting Series will be set using the following rules:

  - For string, bytes, or integer name_or_index (or a list of these, for a nested selection), the Series name is set to the selected field’s name.

  - For a `pyarrow.compute.Expression`, this is set to the string form of the expression.

  - For list-like name_or_index, the name will be set to the name of the final field selected.

  Examples

      >>> import pyarrow as pa
      >>> s = pd.Series(
      ...     [
      ...         {"version": 1, "project": "pandas"},
      ...         {"version": 2, "project": "pandas"},
      ...         {"version": 1, "project": "numpy"},
      ...     ],
      ...     dtype=pd.ArrowDtype(pa.struct(
      ...         [("version", pa.int64()), ("project", pa.string())]
      ...     ))
      ... )

  Extract by field name.

      >>> s.struct.field("project")
      0    pandas
      1    pandas
      2     numpy
      Name: project, dtype: string[pyarrow]

  Extract by field index.

      >>> s.struct.field(0)
      0    1
      1    2
      2    1
      Name: version, dtype: int64[pyarrow]

  Or an expression

      >>> import pyarrow.compute as pc
      >>> s.struct.field(pc.field("project"))
      0    pandas
      1    pandas
      2     numpy
      Name: project, dtype: string[pyarrow]

  For nested struct types, you can pass a list of values to index multiple levels:

      >>> version_type = pa.struct([
      ...     ("major", pa.int64()),
      ...     ("minor", pa.int64()),
      ... ])
      >>> s = pd.Series(
      ...     [
      ...         {"version": {"major": 1, "minor": 5}, "project": "pandas"},
      ...         {"version": {"major": 2, "minor": 1}, "project": "pandas"},
      ...         {"version": {"major": 1, "minor": 26}, "project": "numpy"},
      ...     ],
      ...     dtype=pd.ArrowDtype(pa.struct(
      ...         [("version", version_type), ("project", pa.string())]
      ...     ))
      ... )
      >>> s.struct.field(["version", "minor"])
      0     5
      1     1
      2    26
      Name: minor, dtype: int64[pyarrow]
      >>> s.struct.field([0, 0])
      0    1
      1    2
      2    1
      Name: major, dtype: int64[pyarrow]