Coverage for python/lsst/images/_transforms/_frame_set.py: 0%

1# This file is part of lsst-images. 

2# 

3# Developed for the LSST Data Management System. 

4# This product includes software developed by the LSST Project 

5# (https://www.lsst.org). 

6# See the COPYRIGHT file at the top-level directory of this distribution 

7# for details of code ownership. 

8# 

9# Use of this source code is governed by a 3-clause BSD-style 

10# license that can be found in the LICENSE file. 

11 

12from __future__ import annotations 

13 

14__all__ = ("FrameLookupError", "FrameSet") 

15 

16from abc import ABC, abstractmethod 

17 

18from ..describe import DescribableMixin 

19from . import _frames # use this import style to facilitate pattern matching 

20from ._transform import Transform 

21 

22 

23class FrameLookupError(LookupError): 

24 """Exception raised when a frame cannot be found in a `FrameSet`.""" 

25 

26 

27class FrameSet(DescribableMixin, ABC): 

28 """A container or factory for `Transform` objects that relates frames. 

29 

30 Notes 

31 ----- 

32 `FrameSet` supposes ``in`` (``__contains__``) tests on individual `Frame` 

33 objects to test whether they are known to the frame set, and indexing 

34 (``__getitem__``) of **pairs** of frames to return a `Transform` that maps 

35 the first to the second. 

36 """ 

37 

38 @abstractmethod 

39 def __contains__(self, frame: _frames.Frame) -> bool: 

40 raise NotImplementedError() 

41 

42 @abstractmethod 

43 def __getitem__[I: _frames.Frame, O: _frames.Frame](self, key: tuple[I, O]) -> Transform[I, O]: 

44 raise NotImplementedError() 

45 

46 def get[I: _frames.Frame, O: _frames.Frame](self, in_frame: I, out_frame: O) -> Transform[I, O] | None: 

47 """Return the `Transform` that maps the two frames, or `None` if at 

48 least one is not known to the `FrameSet`. 

49 

50 Parameters 

51 ---------- 

52 in_frame 

53 Frame to transform from. 

54 out_frame 

55 Frame to transform to. 

56 """ 

57 try: 

58 return self[in_frame, out_frame] 

59 except FrameLookupError: 

60 return None