lsst.afw  22.0.1-29-g184b6e44e+8b185d4e2d
_disableArithmetic.py
Go to the documentation of this file.
1 # This file is part of afw.
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 # 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 <https://www.gnu.org/licenses/>.
21 
22 from ._imageLib import ImageSliceF, ImageSliceD
23 
24 __all__ = ("disableImageArithmetic", "disableMaskArithmetic")
25 
26 
27 def wrapNotImplemented(cls, attr):
28  """Wrap a method providing a helpful error message about image arithmetic
29 
30  Parameters
31  ----------
32  cls : `type`
33  Class in which the method is to be defined.
34  attr : `str`
35  Name of the method.
36 
37  Returns
38  -------
39  method : callable
40  Wrapped method.
41  """
42  existing = getattr(cls, attr, None)
43 
44  def notImplemented(self, other):
45  """Provide a helpful error message about image arithmetic
46 
47  Unless we're operating on an ImageSlice, in which case it might be
48  defined.
49 
50  Parameters
51  ----------
52  self : subclass of `lsst.afw.image.ImageBase`
53  Image someone's attempting to do arithmetic with.
54  other : anything
55  The operand of the arithmetic operation.
56  """
57  if existing is not None and isinstance(other, (ImageSliceF, ImageSliceD)):
58  return existing(self, other)
59  raise NotImplementedError("This arithmetic operation is not implemented, in order to prevent the "
60  "accidental proliferation of temporaries. Please use the in-place "
61  "arithmetic operations (e.g., += instead of +) or operate on the "
62  "underlying arrays.")
63  return notImplemented
64 
65 
67  """Add helpful error messages about image arithmetic"""
68  for attr in ("__add__", "__sub__", "__mul__", "__truediv__",
69  "__radd__", "__rsub__", "__rmul__", "__rtruediv__"):
70  setattr(cls, attr, wrapNotImplemented(cls, attr))
71 
72 
74  """Add helpful error messages about mask arithmetic"""
75  for attr in ("__or__", "__and__", "__xor__",
76  "__ror__", "__rand__", "__rxor__"):
77  setattr(cls, attr, wrapNotImplemented(cls, attr))