pandas.Series.struct.field — pandas 2.2.3 documentation (original) (raw)

Series.struct.field(name_or_index)[source]#

Extract a child field of a struct as a Series.

Parameters:

name_or_indexstr | 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.

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]