Coverage for python / lsst / daf / butler / queries / expressions / categorize.py: 64%

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/>. 

27from __future__ import annotations 

28 

29__all__ = () # all symbols intentionally private; for internal package use. 

30 

31import enum 

32 

33 

34class ExpressionConstant(enum.Enum): 

35 """Enumeration for constants recognized in all expressions.""" 

36 

37 NULL = "null" 

38 INGEST_DATE = "ingest_date" 

39 

40 

41def categorizeConstant(name: str) -> ExpressionConstant | None: 

42 """Categorize an identifier in a parsed expression as one of a few global 

43 constants. 

44 

45 Parameters 

46 ---------- 

47 name : `str` 

48 Identifier to categorize. Case-insensitive. 

49 

50 Returns 

51 ------- 

52 categorized : `ExpressionConstant` or `None` 

53 Enumeration value if the string represents a constant, `None` 

54 otherwise. 

55 """ 

56 try: 

57 return ExpressionConstant(name.lower()) 

58 except ValueError: 

59 return None