Coverage for python/lsst/daf/butler/delegates/arrowastropy.py: 45%
23 statements
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« prev ^ index » next coverage.py v7.5.1, created at 2024-05-07 02:46 -0700
1# This file is part of daf_butler.
2#
3# Developed for the LSST Data Management System.
4# This product includes software developed by the LSST Project
5# (http://www.lsst.org).
6# See the COPYRIGHT file at the top-level directory of this distribution
7# for details of code ownership.
8#
9# This software is dual licensed under the GNU General Public License and also
10# under a 3-clause BSD license. Recipients may choose which of these licenses
11# to use; please see the files gpl-3.0.txt and/or bsd_license.txt,
12# respectively. If you choose the GPL option then the following text applies
13# (but note that there is still no warranty even if you opt for BSD instead):
14#
15# This program is free software: you can redistribute it and/or modify
16# it under the terms of the GNU General Public License as published by
17# the Free Software Foundation, either version 3 of the License, or
18# (at your option) any later version.
19#
20# This program is distributed in the hope that it will be useful,
21# but WITHOUT ANY WARRANTY; without even the implied warranty of
22# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
23# GNU General Public License for more details.
24#
25# You should have received a copy of the GNU General Public License
26# along with this program. If not, see <http://www.gnu.org/licenses/>.
28"""Support for reading Astropy tables with the Arrow formatter."""
29from __future__ import annotations
31from typing import Any
33import astropy.table as atable
34from lsst.daf.butler.formatters.parquet import ArrowAstropySchema
35from lsst.utils.introspection import get_full_type_name
37from .arrowtable import ArrowTableDelegate
39__all__ = ["ArrowAstropyDelegate"]
42class ArrowAstropyDelegate(ArrowTableDelegate):
43 """Delegate that understands the ``ArrowAstropy`` storage class."""
45 _datasetType = atable.Table
47 def getComponent(self, composite: atable.Table, componentName: str) -> Any:
48 """Get a component from an astropy table stored via ArrowAstropy.
50 Parameters
51 ----------
52 composite : `~astropy.table.Table`
53 Astropy table to access component.
54 componentName : `str`
55 Name of component to retrieve.
57 Returns
58 -------
59 component : `object`
60 The component.
62 Raises
63 ------
64 AttributeError
65 The component can not be found.
66 """
67 match componentName:
68 case "columns":
69 return list(composite.columns.keys())
70 case "schema":
71 return ArrowAstropySchema(composite)
72 case "rowcount":
73 return len(composite)
75 raise AttributeError(
76 f"Do not know how to retrieve component {componentName} from {get_full_type_name(composite)}"
77 )
79 def _getColumns(self, inMemoryDataset: atable.Table) -> list[str]:
80 return inMemoryDataset.columns.keys()
82 def _selectColumns(self, inMemoryDataset: atable.Table, columns: list[str]) -> atable.Table:
83 return inMemoryDataset[columns]