bugfix: Add access by operator [] to pydantic.BaseModel base structures for keep backward compatybility (#579)

Author: Czaki

package/PartSegCore/algorithm_describe_base.py

@@ -4,6 +4,7 @@
 import warnings
 from abc import ABC, ABCMeta, abstractmethod
 from enum import Enum
+from functools import wraps
 
 from nme import REGISTER, class_to_str
 from pydantic import BaseModel as PydanticBaseModel
@@ -416,7 +417,29 @@ def get_default(cls):
         return cls(name=name, values=cls[name].get_default_values())
 
 
-class ROIExtractionProfile(BaseModel):
+class ROIExtractionProfileMeta(ModelMetaclass):
+    def __new__(cls, name, bases, attrs, **kwargs):
+        cls2 = super().__new__(cls, name, bases, attrs, **kwargs)
+
+        def allow_positional_args(func):
+            @wraps(func)
+            def _wraps(self, *args, **kwargs):
+                if len(args) > 0:
+                    warnings.warn(
+                        "Positional arguments are deprecated, use keyword arguments instead",
+                        FutureWarning,
+                        stacklevel=2,
+                    )
+                    kwargs.update(dict(zip(self.__fields__, args)))
+                return func(self, **kwargs)
+
+            return _wraps
+
+        cls2.__init__ = allow_positional_args(cls2.__init__)
+        return cls2
+
+
+class ROIExtractionProfile(BaseModel, metaclass=ROIExtractionProfileMeta):  # pylint: disable=E1139
     """
     :ivar str ~.name: name for segmentation profile
     :ivar str ~.algorithm: Name of algorithm

package/PartSegCore/utils.py

@@ -2,6 +2,7 @@
 import inspect
 import itertools
 import typing
+import warnings
 import weakref
 from abc import ABC, abstractmethod
 from collections import defaultdict
@@ -408,6 +409,12 @@ class BaseModel(PydanticBaseModel):
     class Config:
         extra = "forbid"
 
+    def __getitem__(self, item):
+        warnings.warn("Access to attribute by [] is deprecated. Use . instead", FutureWarning, stacklevel=2)
+        if item in self.__fields__:
+            return getattr(self, item)
+        raise KeyError(f"{item} not found in {self.__class__.__name__}")
+
 
 def iterate_names(base_name: str, data_dict, max_length=None) -> typing.Optional[str]:
     if base_name not in data_dict:

package/tests/test_PartSegCore/test_algorithm_describe_base.py

@@ -11,6 +11,7 @@
     AlgorithmDescribeBase,
     AlgorithmProperty,
     AlgorithmSelection,
+    ROIExtractionProfile,
     _GetDescriptionClass,
     base_model_to_algorithm_property,
 )
@@ -318,3 +319,9 @@ def get_fields(cls) -> typing.List[typing.Union[AlgorithmProperty, str]]:
             assert len(SampleSubAlgorithm.get_fields_dict()) == 2
         with pytest.warns(FutureWarning, match=r"Class has __argument_class__ defined"):
             assert SampleSubAlgorithm.get_default_values() == {"name": 1, "name2": 3.0}
+
+
+def test_roi_extraction_profile():
+    ROIExtractionProfile(name="aaa", algorithm="aaa", values={})
+    with pytest.warns(FutureWarning):
+        ROIExtractionProfile("aaa", "aaa", {})

package/tests/test_PartSegCore/test_utils.py

@@ -6,6 +6,7 @@
 
 from PartSegCore.json_hooks import PartSegEncoder, partseg_object_hook
 from PartSegCore.utils import (
+    BaseModel,
     CallbackFun,
     CallbackMethod,
     EventedDict,
@@ -277,3 +278,20 @@ def test_iterate_names():
     for _ in range(85):
         input_set.add(iterate_names("a" * 5, input_set))
     assert iterate_names("a" * 5, input_set) is None
+
+
+def test_base_model_getitem():
+    class SampleModel(BaseModel):
+        a: int = 1
+        b: float = 2.0
+        c: str = "3"
+
+    ob = SampleModel()
+    with pytest.warns(FutureWarning, match=r"Access to attribute by \[\] is deprecated\. Use \. instead"):
+        assert ob["a"] == 1
+    with pytest.warns(FutureWarning, match=r"Access to attribute by \[\] is deprecated\. Use \. instead"):
+        assert ob["b"] == 2.0
+    with pytest.warns(FutureWarning, match=r"Access to attribute by \[\] is deprecated\. Use \. instead"):
+        assert ob["c"] == "3"
+    with pytest.raises(KeyError):
+        ob["d"]  # pylint: disable=pointless-statement