Coverage for python/lsst/daf/butler/delegates/arrownumpydict.py: 94%
24 statements
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« prev ^ index » next coverage.py v7.2.7, created at 2023-07-21 09:54 +0000
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 program is free software: you can redistribute it and/or modify
10# it under the terms of the GNU General Public License as published by
11# the Free Software Foundation, either version 3 of the License, or
12# (at your option) any later version.
13#
14# This program is distributed in the hope that it will be useful,
15# but WITHOUT ANY WARRANTY; without even the implied warranty of
16# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17# GNU General Public License for more details.
18#
19# You should have received a copy of the GNU General Public License
20# along with this program. If not, see <http://www.gnu.org/licenses/>.
22"""Support for reading dictionaries of numpy arrays with the Arrow
23formatter.
24"""
25from __future__ import annotations
27from typing import Any
29import numpy as np
30from lsst.daf.butler.formatters.parquet import ArrowNumpySchema, _numpy_dict_to_dtype
31from lsst.utils.introspection import get_full_type_name
33from .arrowtable import ArrowTableDelegate
35__all__ = ["ArrowNumpyDictDelegate"]
38class ArrowNumpyDictDelegate(ArrowTableDelegate):
39 """Delegate that understands the ``ArrowNumpyDict`` storage class."""
41 _datasetType = dict
43 def getComponent(self, composite: dict[str, np.ndarray], componentName: str) -> Any:
44 """Get a component from a dict of numpy arrays stored via
45 ArrowNumpyDict.
47 Parameters
48 ----------
49 composite : `~numpy.ndarray`
50 Numpy table to access component.
51 componentName : `str`
52 Name of component to retrieve.
54 Returns
55 -------
56 component : `object`
57 The component.
59 Raises
60 ------
61 AttributeError
62 The component can not be found.
63 """
64 match componentName:
65 case "columns":
66 return list(composite.keys())
67 case "schema":
68 dtype, _ = _numpy_dict_to_dtype(composite)
69 return ArrowNumpySchema(dtype)
70 case "rowcount": 70 ↛ 73line 70 didn't jump to line 73, because the pattern on line 70 never matched
71 return len(composite[list(composite.keys())[0]])
73 raise AttributeError(
74 f"Do not know how to retrieve component {componentName} from {get_full_type_name(composite)}"
75 )
77 def _getColumns(self, inMemoryDataset: dict[str, np.ndarray]) -> list[str]:
78 return list(inMemoryDataset.keys())
80 def _selectColumns(
81 self, inMemoryDataset: dict[str, np.ndarray], columns: list[str]
82 ) -> dict[str, np.ndarray]:
83 return {column: inMemoryDataset[column] for column in columns}