Coverage for python/lsst/daf/butler/delegates/arrownumpydict.py: 94%
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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 dictionaries of numpy arrays with the Arrow
29formatter.
30"""
31from __future__ import annotations
33from typing import Any
35import numpy as np
36from lsst.daf.butler.formatters.parquet import ArrowNumpySchema, _numpy_dict_to_dtype
37from lsst.utils.introspection import get_full_type_name
39from .arrowtable import ArrowTableDelegate
41__all__ = ["ArrowNumpyDictDelegate"]
44class ArrowNumpyDictDelegate(ArrowTableDelegate):
45 """Delegate that understands the ``ArrowNumpyDict`` storage class."""
47 _datasetType = dict
49 def getComponent(self, composite: dict[str, np.ndarray], componentName: str) -> Any:
50 """Get a component from a dict of numpy arrays stored via
51 ArrowNumpyDict.
53 Parameters
54 ----------
55 composite : `~numpy.ndarray`
56 Numpy table to access component.
57 componentName : `str`
58 Name of component to retrieve.
60 Returns
61 -------
62 component : `object`
63 The component.
65 Raises
66 ------
67 AttributeError
68 The component can not be found.
69 """
70 match componentName:
71 case "columns":
72 return list(composite.keys())
73 case "schema":
74 dtype, _ = _numpy_dict_to_dtype(composite)
75 return ArrowNumpySchema(dtype)
76 case "rowcount": 76 ↛ 79line 76 didn't jump to line 79, because the pattern on line 76 always matched
77 return len(composite[list(composite.keys())[0]])
79 raise AttributeError(
80 f"Do not know how to retrieve component {componentName} from {get_full_type_name(composite)}"
81 )
83 def _getColumns(self, inMemoryDataset: dict[str, np.ndarray]) -> list[str]:
84 return list(inMemoryDataset.keys())
86 def _selectColumns(
87 self, inMemoryDataset: dict[str, np.ndarray], columns: list[str]
88 ) -> dict[str, np.ndarray]:
89 return {column: inMemoryDataset[column] for column in columns}