_SimpleGenericMap.py
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21
22 __all__ = ["SimpleGenericMap"]
23
24 from lsst.utils import continueClass
25 from ._typehandling import SimpleGenericMapS
26 from ._GenericMap import MutableGenericMap, AutoKeyMeta
27
28
29 class SimpleGenericMap(MutableGenericMap, metaclass=AutoKeyMeta):
30  """A dict-like ~collections.abc.MutableMapping for use when sharing a
31  map between C++ and Python.
32
33  For compatibility with C++, SimpleGenericMap has the following
34  restrictions:
35
36  - all keys must be of the same type
37  - values must be built-in types or subclasses of
38  lsst.afw.typehandling.Storable. Almost any user-defined class in
39  C++ or Python can have ~lsst.afw.typehandling.Storable as a mixin.
40
41  As a safety precaution, ~lsst.afw.typehandling.Storable objects that are
42  added from C++ may be copied when you retrieve them from Python, making it
43  impossible to modify them in-place. This issue does not affect objects that
44  are added from Python, or objects that are always passed by
45  :cpp:class:shared_ptr in C++.
46
47  Parameters
48  ----------
49  mapping : collections.abc.Mapping, optional
50  iterable : iterable, optional
51  dtype : type, optional
52  The type of key the map accepts. Not required if mapping or
53  iterable is provided.
54  **kwargs
55  Aside from the dtype keyword, a SimpleGenericMap takes the same
56  input arguments as dict.
57  """
58  @classmethod
59  def fromkeys(cls, iterable, value=None):
60  return cls({key: value for key in iterable})
61
62
63 SimpleGenericMap.register(str, SimpleGenericMapS)
64
65
66 # pybind11-generated constructor, can only create empty map
67 _oldInit = SimpleGenericMapS.__init__
68
69
70 @continueClass # noqa: F811 (FIXME: remove for py 3.8+)
71 class SimpleGenericMapS: # noqa: F811
72  def __init__(self, source=None, **kwargs):
73  _oldInit(self)
74  if source:
75  self.update(source, **kwargs)
76  else:
77  self.update(**kwargs)