quality & typing fixes

pyproject.toml

@@ -35,8 +35,8 @@ classifiers = [
 dependencies = [
     'importlib-metadata; python_version<"3.9"',
     'packaging',
-    'pydantic',
-    'runtype'
+    'frozendict',
+    'typeguard'
 ]
 dynamic = ["version"]
 

src/dabmodel/__init__.py

@@ -25,4 +25,6 @@ from .model import (
     InvalidFieldValue,
     InvalidFieldAnnotation,
     IncompletelyAnnotatedField,
+    ImportForbidden,
+    FunctionForbidden,
 )

src/dabmodel/model.py

@@ -1,9 +1,33 @@
-from typing import Optional, TypeVar, Generic, Union, get_origin, get_args, List, Dict, Any, Tuple, Set, Annotated, FrozenSet
-from types import UnionType
-from frozendict import deepfreeze
-from copy import deepcopy, copy
-from pprint import pprint
+""" dabmodel model module
+This module implements DAB model classes.
+This module contains metaclass and bases classes used to create models.
+BaseAppliance can be used to create a new Appliance Data.
+BaseFeature can be used to create new Appliance's Features."""
 
+from typing import (
+    Optional,
+    TypeVar,
+    Generic,
+    Union,
+    get_origin,
+    get_args,
+    List,
+    Dict,
+    Any,
+    Tuple,
+    Set,
+    Annotated,
+    FrozenSet,
+    Callable,
+    Type,
+)
+from types import UnionType, FunctionType, SimpleNamespace
+from copy import deepcopy, copy
+
+# from pprint import pprint
+import math
+
+from frozendict import deepfreeze
 from typeguard import check_type, TypeCheckError, CollectionCheckStrategy
 
 ALLOWED_ANNOTATIONS = {
@@ -34,43 +58,149 @@ ALLOWED_MODEL_FIELDS_TYPES = (str, int, float, complex, bool, bytes)
 ALLOWED_MODEL_FIELDS_CONTAINERS = (dict, list, set, frozenset, tuple)
 
 
-TV_ALLOWED_MODEL_FIELDS_TYPES = TypeVar("TV_ALLOWED_MODEL_FIELDS_TYPES", *ALLOWED_MODEL_FIELDS_TYPES, *ALLOWED_MODEL_FIELDS_CONTAINERS)
+# TV_ALLOWED_MODEL_FIELDS_TYPES = TypeVar("TV_ALLOWED_MODEL_FIELDS_TYPES", *ALLOWED_MODEL_FIELDS_TYPES, *ALLOWED_MODEL_FIELDS_CONTAINERS)
 
 
-class DABModelException(Exception): ...
+class DABModelException(Exception):
+    """DABModelException Exception class
+    Base Exception for DABModelException class
+    """
 
 
-class MultipleInheritanceForbidden(DABModelException): ...
+class MultipleInheritanceForbidden(DABModelException):
+    """MultipleInheritanceForbidden Exception class
+    Multiple inheritance is forbidden when using dabmodel
+    """
 
 
-class BrokenInheritance(DABModelException): ...
+class BrokenInheritance(DABModelException):
+    """BrokenInheritance Exception class
+    inheritance chain is broken
+    """
 
 
-class ReadOnlyField(DABModelException): ...
+class ReadOnlyField(DABModelException):
+    """ReadOnlyField Exception class
+    The used Field is ReadOnly
+    """
 
 
-class NewFieldForbidden(DABModelException): ...
+class NewFieldForbidden(DABModelException):
+    """NewFieldForbidden Exception class
+    Field creation is forbidden
+    """
 
 
-class InvalidFieldAnnotation(DABModelException): ...
+class InvalidFieldAnnotation(DABModelException):
+    """InvalidFieldAnnotation Exception class
+    The field annotation is invalid
+    """
 
 
-class NotAnnotatedField(InvalidFieldAnnotation): ...
+class InvalidInitializerType(DABModelException):
+    """InvalidInitializerType Exception class
+    The initializer is not a valid type
+    """
 
 
-class IncompletelyAnnotatedField(InvalidFieldAnnotation): ...
+class NotAnnotatedField(InvalidFieldAnnotation):
+    """NotAnnotatedField Exception class
+    The Field is not Annotated
+    """
 
 
-class ReadOnlyFieldAnnotation(DABModelException): ...
+class IncompletelyAnnotatedField(InvalidFieldAnnotation):
+    """IncompletelyAnnotatedField Exception class
+    The field annotation is incomplete
+    """
 
 
-class InvalidFieldValue(DABModelException): ...
+class ReadOnlyFieldAnnotation(DABModelException):
+    """ReadOnlyFieldAnnotation Exception class
+    Field annotation connot be modified
+    """
+
+
+class InvalidFieldValue(DABModelException):
+    """InvalidFieldValue Exception class
+    The Field value is invalid
+    """
+
+
+class NonExistingField(DABModelException):
+    """NonExistingField Exception class
+    The given Field is non existing
+    """
+
+
+class ImportForbidden(DABModelException):
+    """ImportForbidden Exception class
+    Imports are forbidden
+    """
+
+
+class FunctionForbidden(DABModelException):
+    """FunctionForbidden Exception class
+    function call are forbidden
+    """
+
+
+ALLOWED_HELPERS_MATH = SimpleNamespace(
+    sqrt=math.sqrt,
+    floor=math.floor,
+    ceil=math.ceil,
+    trunc=math.trunc,
+    fabs=math.fabs,
+    copysign=math.copysign,
+    hypot=math.hypot,
+    exp=math.exp,
+    log=math.log,
+    log10=math.log10,
+    sin=math.sin,
+    cos=math.cos,
+    tan=math.tan,
+    atan2=math.atan2,
+    radians=math.radians,
+    degrees=math.degrees,
+)
+
+ALLOWED_HELPERS_DEFAULT = {
+    "math": ALLOWED_HELPERS_MATH,
+    "print": print,
+    # Numbers & reducers (pure, deterministic)
+    "abs": abs,
+    "round": round,
+    "min": min,
+    "max": max,
+    "sum": sum,
+    # Introspection-free basics
+    "len": len,
+    "sorted": sorted,
+    # Basic constructors (for copy-on-write patterns)
+    "tuple": tuple,
+    "list": list,
+    "dict": dict,
+    "set": set,
+    # Simple casts if they need to normalize types
+    "int": int,
+    "float": float,
+    "str": str,
+    "bool": bool,
+    "bytes": bytes,
+    "complex": complex,
+    # Easy iteration helpers (optional but handy)
+    "range": range,
+}
+
+
+def _blocked_import(*args, **kwargs):
+    raise ImportForbidden("imports disabled in __initializer")
 
 
 def _resolve_annotation(ann):
     if isinstance(ann, str):
         # Safe eval against a **whitelist** only
-        return eval(ann, {"__builtins__": {}}, ALLOWED_ANNOTATIONS)
+        return eval(ann, {"__builtins__": {}}, ALLOWED_ANNOTATIONS)  # pylint: disable=eval-used
     return ann
 
 
@@ -88,15 +218,15 @@ def _peel_annotated(t: Any) -> Any:
             return t
 
 
-def _check_annotation_definition(_type) -> bool:
+def _check_annotation_definition(_type) -> bool:  # pylint: disable=too-complex,too-many-return-statements
     _type = _peel_annotated(_type)
     # handle Optional[] and Union[None,...]
     if (get_origin(_type) is Union or get_origin(_type) is UnionType) and type(None) in get_args(_type):
-        return all([_check_annotation_definition(_) for _ in get_args(_type) if _ is not type(None)])
+        return all(_check_annotation_definition(_) for _ in get_args(_type) if _ is not type(None))
 
     # handle other Union[...]
     if get_origin(_type) is Union or get_origin(_type) is UnionType:
-        return all([_check_annotation_definition(_) for _ in get_args(_type)])
+        return all(_check_annotation_definition(_) for _ in get_args(_type))
 
     # handle Dict[...]
     if get_origin(_type) is dict:
@@ -112,127 +242,240 @@ def _check_annotation_definition(_type) -> bool:
             raise IncompletelyAnnotatedField(f"Annotation requires inner definition: {_type}")
         if len(inner_types) == 2 and inner_types[1] is Ellipsis:
             return _check_annotation_definition(inner_types[0])
-        return all([_check_annotation_definition(_) for _ in inner_types])
+        return all(_check_annotation_definition(_) for _ in inner_types)
 
     # handle Set[],Tuple[],FrozenSet[],List[]
     if get_origin(_type) in [set, frozenset, tuple, list]:
         inner_types = get_args(_type)
         if len(inner_types) == 0:
             raise IncompletelyAnnotatedField(f"Annotation requires inner definition: {_type}")
-        return all([_check_annotation_definition(_) for _ in inner_types])
+        return all(_check_annotation_definition(_) for _ in inner_types)
 
     if _type in ALLOWED_MODEL_FIELDS_TYPES:
         return True
     return False
 
 
-class BaseConstraint(Generic[TV_ALLOWED_MODEL_FIELDS_TYPES]):
+T_Field = TypeVar("T_Field")
+
+
+class BaseConstraint(Generic[T_Field]):
+    """BaseConstraint class
+    Base class for Field's constraints
+    """
+
     _bound_type: type
 
     def __init__(self): ...
 
-    def check(self, value: TV_ALLOWED_MODEL_FIELDS_TYPES) -> bool: ...
+    def check(self, value: T_Field) -> bool:
+        """Check if a Constraint is completed"""
+        return True
 
 
 def _deepfreeze(value):
+    """recursive freeze helper function"""
     if isinstance(value, dict):
         return deepfreeze(value)
-    elif isinstance(value, set):
+    if isinstance(value, set):
         return frozenset(_deepfreeze(v) for v in value)
-    elif isinstance(value, list):
+    if isinstance(value, list):
         return tuple(_deepfreeze(v) for v in value)
-    elif isinstance(value, tuple):
+    if isinstance(value, tuple):
         return tuple(_deepfreeze(v) for v in value)
     return value
 
 
 class DABFieldInfo:
-    def __init__(self, *, doc: str = "", constraints: list[BaseConstraint] = []):
+    """This Class allows to describe a Field in Appliance class"""
+
+    def __init__(self, *, doc: str = "", constraints: Optional[list[BaseConstraint]] = None):
         self._doc: str = doc
-        self._constraints: list[BaseConstraint] = constraints
+        self._constraints: list[BaseConstraint]
+        if constraints is None:
+            self._constraints = []
+        else:
+            self._constraints = constraints
 
     @property
     def doc(self):
+        """Returns Field's documentation"""
         return self._doc
 
     @property
-    def constraints(self):
+    def constraints(self) -> list[BaseConstraint[Any]]:
+        """Returns Field's constraints"""
         return self._constraints
 
 
-class DABField(Generic[TV_ALLOWED_MODEL_FIELDS_TYPES]):
-    def __init__(self, name: str, v: Optional[TV_ALLOWED_MODEL_FIELDS_TYPES], a: Any, i: str):
+class DABField(Generic[T_Field]):
+    """This class describe a Field in Schema"""
+
+    def __init__(self, name: str, v: Optional[T_Field], a: Any, i: DABFieldInfo):
         self._name: str = name
         self._source: Optional[type] = None
-        self._default_value: Optional[TV_ALLOWED_MODEL_FIELDS_TYPES] = v
-        self._value: Optional[TV_ALLOWED_MODEL_FIELDS_TYPES] = v
+        self._default_value: Optional[T_Field] = v
+        self._value: Optional[T_Field] = v
         self._annotations: Any = a
         self._info: DABFieldInfo = i
-        self._constraints: List[BaseConstraint] = i.constraints
+        self._constraints: List[BaseConstraint[Any]] = i.constraints
 
     def add_source(self, s: type) -> None:
+        """Adds source Appliance to the Field"""
         self._source = s
 
     @property
     def doc(self):
+        """Returns Field's documentation"""
         return self._info.doc
 
     def add_constraint(self, c: BaseConstraint) -> None:
+        """Adds constraint to the Field"""
         self._constraints.append(c)
 
     @property
     def constraints(self) -> list[BaseConstraint]:
+        """Returns Field's constraint"""
         return self._info.constraints
 
     @property
-    def default_value(self):
+    def default_value(self) -> Any:
+        """Returns Field's default value (frozen)"""
         return _deepfreeze(self._default_value)
 
-    def update_value(self, v: Optional[TV_ALLOWED_MODEL_FIELDS_TYPES] = None) -> None:
+    def update_value(self, v: Optional[T_Field] = None) -> None:
+        """Updates Field's value"""
         self._value = v
 
     @property
-    def value(self):
+    def value(self) -> Any:
+        """Returns Field's value (frosen)"""
         return _deepfreeze(self._value)
 
+    @property
+    def raw_value(self) -> Optional[T_Field]:
+        """Returns Field's value"""
+        return self._value
+
     @property
     def annotations(self) -> Any:
+        """Returns Field's annotation"""
         return self._annotations
 
 
-class FrozenDABField(Generic[TV_ALLOWED_MODEL_FIELDS_TYPES]):
+class FrozenDABField(Generic[T_Field]):
+    """FrozenDABField class
+    a read-only proxy of a Field
+    """
+
     def __init__(self, inner_field: DABField):
         self._inner_field = inner_field
 
     @property
-    def doc(self):
-        return self._inner_field.doc
+    def doc(self) -> str:
+        """Returns Field's documentation (frozen)"""
+        return _deepfreeze(self._inner_field.doc)
 
     @property
-    def constraints(self):
+    def constraints(self) -> tuple[BaseConstraint]:
+        """Returns Field's constraint (frozen)"""
         return _deepfreeze(self._inner_field.constraints)
 
     @property
-    def default_value(self):
+    def default_value(self) -> Any:
+        """Returns Field's default value (frozen)"""
         return self._inner_field.default_value
 
     @property
-    def value(self):
+    def value(self) -> Any:
+        """Returns Field's value (frosen)"""
         return self._inner_field.value
 
     @property
     def annotations(self) -> Any:
+        """Returns Field's annotation (frozen)"""
         return _deepfreeze(self._inner_field.annotations)
 
 
+class ModelSpecView:
+    """ModelSpecView class
+    A class that will act as fake BaseElement proxy to allow setting values"""
+
+    __slots__ = ("_vals", "_types", "_touched", "_name", "_module")
+
+    def __init__(self, values: dict, types_map: dict[str, type], name, module):
+        object.__setattr__(self, "_vals", dict(values))
+        object.__setattr__(self, "_types", types_map)
+        object.__setattr__(self, "_touched", set())
+        object.__setattr__(self, "_name", name)
+        object.__setattr__(self, "_module", module)
+
+    @property
+    def __name__(self) -> str:
+        """returns proxified class' name"""
+        return self._name
+
+    @property
+    def __module__(self) -> str:
+        """returns proxified module's name"""
+        return self._module
+
+    @__module__.setter
+    def __module__(self, value):
+        pass
+
+    def __getattr__(self, name):
+        """internal proxy getattr"""
+        if name not in self._types:
+            raise AttributeError(f"Unknown field {name}")
+        return self._vals[name]
+
+    def __setattr__(self, name, value):
+        """internal proxy setattr"""
+        if name not in self._types:
+            raise NonExistingField(f"Cannot set unknown field {name}")
+        T = self._types[name]
+
+        try:
+            check_type(
+                value,
+                T,
+                collection_check_strategy=CollectionCheckStrategy.ALL_ITEMS,
+            )
+        except TypeCheckError as exp:
+            raise InvalidFieldValue(f"Field <{name}> value is not of expected type {T}.") from exp
+
+        self._vals[name] = value
+        self._touched.add(name)
+
+    def export(self) -> dict:
+        """exports all proxified values"""
+        return dict(self._vals)
+
+
+T_Meta = TypeVar("T_Meta", bound="BaseMeta")
+T_BE = TypeVar("T_BE", bound="BaseElement")
+
+
 class BaseMeta(type):
-    def __new__(mcls, name, bases, namespace):
+    """metaclass to use to build BaseElement"""
+
+    modified_field: Dict[str, Any] = {}
+    new_fields: Dict[str, DABField[Any]] = {}
+    initializer: Optional[Callable[..., Any]] = None
+    __DABSchema__: dict[str, Any] = {}
+
+    @classmethod
+    def pre_check(
+        mcs: type["BaseMeta"], name: str, bases: tuple[type[Any], ...], namespace: dict[str, Any]  # pylint: disable=unused-argument
+    ) -> None:
+        """early BaseElement checks"""
         # print("__NEW__ Defining:", name, "with keys:", list(namespace))
 
         if len(bases) > 1:
             raise MultipleInheritanceForbidden("Multiple inheritance is not supported by dabmodel")
-        elif len(bases) == 0:  # base class (BaseElement)
-            namespace["__DABSchema__"] = dict()
+        if len(bases) == 0:  # base class (BaseElement)
+            namespace["__DABSchema__"] = {}
         else:  # standard inheritance
             # check class tree origin
             if "__DABSchema__" not in dir(bases[0]):
@@ -245,80 +488,136 @@ class BaseMeta(type):
             for _funknown in [_ for _ in namespace["__annotations__"] if _ not in namespace.keys()]:
                 namespace[_funknown] = None
 
+    @classmethod
+    def pre_processing_modified(
+        mcs: type["BaseMeta"], name: str, bases: tuple[type[Any], ...], namespace: dict[str, Any], _fname: str, _fvalue: Any
+    ):  # pylint: disable=unused-argument
+        """preprocessing BaseElement modified Fields"""
+        # print(f"Modified field: {_fname}")
+        if "__annotations__" in namespace and _fname in namespace["__annotations__"]:
+            raise ReadOnlyFieldAnnotation("annotations cannot be modified on derived classes")
+        try:
+            check_type(
+                _fvalue,
+                namespace["__DABSchema__"][_fname].annotations,
+                collection_check_strategy=CollectionCheckStrategy.ALL_ITEMS,
+            )
+        except TypeCheckError as exp:
+            raise InvalidFieldValue(
+                f"Field <{_fname}> New Field value is not of expected type {bases[0].__annotations__[_fname]}."
+            ) from exp
+        mcs.modified_field[_fname] = _fvalue
+
+    @classmethod
+    def pre_processing_new(
+        mcs: type["BaseMeta"], name: str, bases: tuple[type[Any], ...], namespace: dict[str, Any], _fname: str, _fvalue: Any
+    ):  # pylint: disable=unused-argument
+        """preprocessing BaseElement new Fields"""
+        # print(f"New field: {_fname}")
+        # print(f"type is: {type(_fvalue)}")
+        # print(f"value is: {_fvalue}")
+
+        # check if field is annotated
+        if "__annotations__" not in namespace or _fname not in namespace["__annotations__"]:
+            raise NotAnnotatedField(f"Every dabmodel Fields must be annotated ({_fname})")
+
+        # check if annotation is allowed
+        if isinstance(namespace["__annotations__"][_fname], str):
+            namespace["__annotations__"][_fname] = _resolve_annotation(namespace["__annotations__"][_fname])
+
+        if not _check_annotation_definition(namespace["__annotations__"][_fname]):
+            raise InvalidFieldAnnotation(f"Field <{_fname}> has not an allowed or valid annotation.")
+
+        _finfo: DABFieldInfo = DABFieldInfo()
+        origin = get_origin(namespace["__annotations__"][_fname])
+        tname = getattr(origin, "__name__", "") or getattr(origin, "__qualname__", "") or str(origin)
+        if "Annotated" in tname:
+            args = get_args(namespace["__annotations__"][_fname])
+            if args:
+                if len(args) > 2:
+                    raise InvalidFieldAnnotation(f"Field <{_fname}> had invalid Annotated value.")
+                if len(args) == 2 and not isinstance(args[1], DABFieldInfo):
+                    raise InvalidFieldAnnotation("Only DABFieldInfo object is allowed as Annotated data.")
+
+                _finfo = args[1]
+
+        # print(f"annotation is: {namespace['__annotations__'][_fname]}")
+        # check if value is valid
+        try:
+            check_type(_fvalue, namespace["__annotations__"][_fname], collection_check_strategy=CollectionCheckStrategy.ALL_ITEMS)
+        except TypeCheckError as exp:
+            raise InvalidFieldValue(f"Value of Field <{_fname}> is not of expected type {namespace['__annotations__'][_fname]}.") from exp
+        mcs.new_fields[_fname] = DABField(_fname, _fvalue, namespace["__annotations__"][_fname], _finfo)
+
+    @classmethod
+    def pre_processing(mcs: type["BaseMeta"], name: str, bases: tuple[type[Any], ...], namespace: dict[str, Any]):
+        """preprocessing BaseElement"""
         # iterating new and modified fields
-        modified_field: Dict[str, Any] = {}
-        new_fields: Dict[str, DABField] = {}
+        mcs.modified_field = {}
+        mcs.new_fields = {}
+        mcs.initializer = None
+        initializer_name: Optional[str] = None
         for _fname, _fvalue in namespace.items():
-            if _fname.startswith("__"):
+            if _fname == f"_{name}__initializer" or (name.startswith("_") and _fname == "__initializer"):
+                if not isinstance(_fvalue, classmethod):
+                    raise InvalidInitializerType()
+                mcs.initializer = _fvalue.__func__
+                if name.startswith("_"):
+                    initializer_name = "__initializer"
+                else:
+                    initializer_name = f"_{name}__initializer"
+            elif _fname.startswith("__"):
                 pass
-            elif _fname == "Constraints" and type(_fvalue) is type:
-                ...
-                # print("FOUND Constraints")
             else:
                 # print(f"Parsing Field: {_fname} / {_fvalue}")
-                # Modified fields
-                if len(bases) == 1 and _fname in namespace["__DABSchema__"].keys():
-                    # print(f"Modified field: {_fname}")
-                    if "__annotations__" in namespace and _fname in namespace["__annotations__"]:
-                        raise ReadOnlyFieldAnnotation("annotations cannot be modified on derived classes")
-                    try:
-                        check_type(
-                            _fvalue,
-                            namespace["__DABSchema__"][_fname].annotations,
-                            collection_check_strategy=CollectionCheckStrategy.ALL_ITEMS,
-                        )
-                    except TypeCheckError as exp:
-                        raise InvalidFieldValue(
-                            f"Field <{_fname}> New Field value is not of expected type {bases[0].__annotations__[_fname]}."
-                        ) from exp
-                    modified_field[_fname] = _fvalue
-                # New fieds
-                else:
-                    # print(f"New field: {_fname}")
-                    # print(f"type is: {type(_fvalue)}")
-                    # print(f"value is: {_fvalue}")
-
-                    # check if field is annotated
-                    if "__annotations__" not in namespace or _fname not in namespace["__annotations__"]:
-                        raise NotAnnotatedField(f"Every dabmodel Fields must be annotated ({_fname})")
-
-                    # check if annotation is allowed
-                    if isinstance(namespace["__annotations__"][_fname], str):
-                        namespace["__annotations__"][_fname] = _resolve_annotation(namespace["__annotations__"][_fname])
-
-                    if not _check_annotation_definition(namespace["__annotations__"][_fname]):
-                        raise InvalidFieldAnnotation(f"Field <{_fname}> has not an allowed or valid annotation.")
-
-                    _finfo: Optional[DABFieldInfo] = DABFieldInfo()
-                    origin = get_origin(namespace["__annotations__"][_fname])
-                    name = getattr(origin, "__name__", "") or getattr(origin, "__qualname__", "") or str(origin)
-                    if "Annotated" in name:
-                        args = get_args(namespace["__annotations__"][_fname])
-                        if args:
-                            if len(args) > 2:
-                                raise InvalidFieldAnnotation(f"Field <{_fname}> had invalid Annotated value.")
-                            if len(args) == 2 and not isinstance(args[1], DABFieldInfo):
-                                raise InvalidFieldAnnotation(f"Only DABFieldInfo object is allowed as Annotated data.")
-
-                            _finfo = args[1]
-
-                    # print(f"annotation is: {namespace['__annotations__'][_fname]}")
-                    # check if value is valid
-                    try:
-                        check_type(
-                            _fvalue, namespace["__annotations__"][_fname], collection_check_strategy=CollectionCheckStrategy.ALL_ITEMS
-                        )
-                    except TypeCheckError as exp:
-                        raise InvalidFieldValue(
-                            f"Value of Field <{_fname}> is not of expected type {namespace['__annotations__'][_fname]}."
-                        ) from exp
-                    new_fields[_fname] = DABField(_fname, _fvalue, namespace["__annotations__"][_fname], _finfo)
-
+                if len(bases) == 1 and _fname in namespace["__DABSchema__"].keys():  # Modified fields
+                    mcs.pre_processing_modified(name, bases, namespace, _fname, _fvalue)
+                else:  # New fieds
+                    mcs.pre_processing_new(name, bases, namespace, _fname, _fvalue)
         # removing modified fields from class (will add them back later)
-        for _fname in new_fields.keys():
+        for _fname in mcs.new_fields:
             del namespace[_fname]
-        for _fname in modified_field.keys():
+        for _fname in mcs.modified_field:
             del namespace[_fname]
+        if mcs.initializer is not None and initializer_name is not None:
+            del namespace[initializer_name]
+
+    @classmethod
+    def call_initializer(
+        mcs: type["BaseMeta"], cls, name: str, bases: tuple[type[Any], ...], namespace: dict[str, Any]
+    ):  # pylint: disable=unused-argument
+        """BaseElement initializer processing"""
+        if mcs.initializer is not None:
+            init_fieldvalues = {}
+            init_fieldtypes = {}
+            for _fname, _fvalue in cls.__DABSchema__.items():
+                init_fieldvalues[_fname] = deepcopy(_fvalue.raw_value)
+                init_fieldtypes[_fname] = _fvalue.annotations
+            fakecls = ModelSpecView(init_fieldvalues, init_fieldtypes, cls.__name__, cls.__module__)
+            safe_globals = {"__builtins__": {"__import__": _blocked_import}, **ALLOWED_HELPERS_DEFAULT}
+            if mcs.initializer.__code__.co_freevars:
+                raise FunctionForbidden("__initializer must not use closures")
+            safe_initializer = FunctionType(
+                mcs.initializer.__code__,
+                safe_globals,
+                name=mcs.initializer.__name__,
+                argdefs=mcs.initializer.__defaults__,
+                closure=None,
+            )
+            safe_initializer(fakecls)  # pylint: disable=not-callable
+            for _fname, _fvalue in fakecls.export().items():
+                try:
+                    check_type(_fvalue, cls.__DABSchema__[_fname].annotations, collection_check_strategy=CollectionCheckStrategy.ALL_ITEMS)
+                except TypeCheckError as exp:
+                    raise InvalidFieldValue(
+                        f"Value of Field <{_fname}> is not of expected type {namespace['__annotations__'][_fname]}."
+                    ) from exp
+                cls.__DABSchema__[_fname].update_value(_fvalue)
+
+    def __new__(mcs: type["BaseMeta"], name: str, bases: tuple[type[Any], ...], namespace: dict[str, Any]) -> Type:
+        """BaseElement new class"""
+        mcs.pre_check(name, bases, namespace)
+        mcs.pre_processing(name, bases, namespace)
 
         orig_setattr = namespace.get("__setattr__", object.__setattr__)
 
@@ -330,32 +629,33 @@ class BaseMeta(type):
                 if hasattr(self, key):
                     raise ReadOnlyField(f"{key} is read-only")
             else:
-                raise NewFieldForbidden(f"creating new fields is not allowed")
+                raise NewFieldForbidden("creating new fields is not allowed")
 
             return orig_setattr(self, key, value)
 
         namespace["__setattr__"] = guarded_setattr
 
-        cls = super().__new__(mcls, name, bases, namespace)
+        _cls = super().__new__(mcs, name, bases, namespace)
 
-        for _fname, _fvalue in modified_field.items():
-            cls.__DABSchema__[_fname] = deepcopy(bases[0].__DABSchema__[_fname])
-            cls.__DABSchema__[_fname].update_value(_fvalue)
+        for _fname, _fvalue in mcs.modified_field.items():
+            _cls.__DABSchema__[_fname] = deepcopy(bases[0].__DABSchema__[_fname])
+            _cls.__DABSchema__[_fname].update_value(_fvalue)
 
-        for _fname, _fvalue in new_fields.items():
-            _fvalue.add_source(cls)
-            cls.__DABSchema__[_fname] = _fvalue
+        for _fname, _fvalue in mcs.new_fields.items():
+            _fvalue.add_source(mcs)
+            _cls.__DABSchema__[_fname] = _fvalue
 
-        return cls
+        mcs.call_initializer(_cls, name, bases, namespace)
 
-    def __call__(cls, *args, **kw):
+        return _cls
+
+    def __call__(cls, *args: Any, **kw: Any):  # intentionally untyped
+        """BaseElement new instance"""
         obj = super().__call__(*args, **kw)
 
-        for _fname in cls.__DABSchema__.keys():
+        for _fname, _fvalue in cls.__DABSchema__.items():
             setattr(obj, _fname, cls.__DABSchema__[_fname].value)
-        # obj.__DABSchema__ = deepfreeze(obj.__DABSchema__)
-        # setattr(obj, "__DABSchema__", deepfreeze(obj.__DABSchema__))
-        inst_schema = dict()
+        inst_schema: dict[str, Any] = {}
         for _fname, _fvalue in cls.__DABSchema__.items():
             inst_schema[_fname] = FrozenDABField(_fvalue)
         setattr(obj, "__DABSchema__", inst_schema)
@@ -363,12 +663,20 @@ class BaseMeta(type):
 
 
 class BaseElement(metaclass=BaseMeta):
-    pass
+    """BaseElement class
+    Base class to apply metaclass and set common Fields.
+    """
 
 
 class BaseFeature(BaseElement):
-    pass
+    """BaseFeature class
+    Base class for Appliance's Features.
+    Features are optional traits of an appliance.
+    """
 
 
 class BaseAppliance(BaseElement):
-    pass
+    """BaseFeature class
+    Base class for Appliance.
+    An appliance is a server configuration / image that is built using appliance's code and Fields.
+    """

src/dabmodel/tools.py

@@ -1,13 +1,17 @@
+"""library's internal tools"""
+
 from uuid import UUID
 from datetime import datetime
 import json
 
 
 class DABJSONEncoder(json.JSONEncoder):
-    def default(self, obj):
-        if isinstance(obj, UUID):
-            # if the obj is uuid, we simply return the value of uuid
-            return obj.hex
-        elif isinstance(obj, datetime):
-            return str(obj)
-        return json.JSONEncoder.default(self, obj)
+    """allows to JSON encode non supported data type"""
+
+    def default(self, o):
+        if isinstance(o, UUID):
+            # if the o is uuid, we simply return the value of uuid
+            return o.hex
+        if isinstance(o, datetime):
+            return str(o)
+        return json.JSONEncoder.default(self, o)

test/test_model.py

@@ -15,6 +15,7 @@ from pathlib import Path
 import textwrap
 from typing import List, Optional, Dict, Union, Tuple, Set, FrozenSet, TypeVar, Generic, Any, Annotated
 from pprint import pprint
+from frozendict import frozendict
 
 print(__name__)
 print(__package__)
@@ -26,6 +27,10 @@ testdir_path = Path(__file__).parent.resolve()
 chdir(testdir_path.parent.resolve())
 
 
+def test_initializer_safe_testfc():
+    eval("print('hi')")
+
+
 class TestConfigWithoutEnabledFlag(unittest.TestCase):
     def setUp(self):
         print("\n->", unittest.TestCase.id(self))
@@ -214,7 +219,7 @@ class TestConfigWithoutEnabledFlag(unittest.TestCase):
         self.immutable_vars__test_field(app2, "StrVar5", "default value", "123")
         self.immutable_vars__test_field(app2, "StrVar6", None, "123")
 
-    @unittest.skip
+    # @unittest.skip
     def test_containers__set(self):
         """Testing first appliance level, and Field types (Set)"""
 
@@ -293,7 +298,7 @@ class TestConfigWithoutEnabledFlag(unittest.TestCase):
             res = subprocess.run([sys.executable, "-c", code], env=env)
             self.assertEqual(res.returncode, 2)
 
-    @unittest.skip
+    # @unittest.skip
     def test_containers__frozenset(self):
         """Testing first appliance level, and Field types (FrozenSet)"""
 
@@ -896,6 +901,280 @@ class TestConfigWithoutEnabledFlag(unittest.TestCase):
             class _(Appliance3):
                 StrVar: int = 12
 
+    def test_containers_field_inheritance(self):
+        """Testing first appliance level, and Field types (annotated)"""
+
+        # class can be created
+        class Appliance1(dm.BaseAppliance):
+            ListStr: list[str] = ["val1", "val2"]
+            Dict1: dict[int, float] = {1: 1.1, 4: 7.6, 91: 23.6}
+            Tuple1: "tuple[str,...]" = ("a", "c")
+            FrozenSet1: frozenset[int] = frozenset({1, 2})
+            Set1: set[int] = set({1, 2})
+
+        # class can be created
+        class Appliance2(Appliance1):
+            ListStr = ["mod val1", "mod val2"]
+            Dict1 = {4: 1.1, 9: 7.6, 51: 23.6}
+            Tuple1 = ("aa", "cc")
+            FrozenSet1 = frozenset({14, 27})
+            Set1 = set({1, 20})
+
+        app1 = Appliance1()
+
+        self.immutable_vars__test_field(app1, "ListStr", ("val1", "val2"), ["val2", "val3"])
+        self.immutable_vars__test_field(app1, "Dict1", {1: 1.1, 4: 7.6, 91: 23.6}, {1: 1.1, 4: 7.6, 91: 23.6})
+        self.immutable_vars__test_field(app1, "Tuple1", ("a", "c"), ("h", "r"))
+        self.immutable_vars__test_field(app1, "FrozenSet1", frozenset({1, 2}), frozenset({4, 0}))
+        self.immutable_vars__test_field(app1, "Set1", frozenset({1, 2}), set({4, 0}))
+
+        self.check_immutable_fields_schema(app1, "ListStr", ("val1", "val2"), ("val1", "val2"), list[str])
+        self.check_immutable_fields_schema(app1, "Dict1", {1: 1.1, 4: 7.6, 91: 23.6}, {1: 1.1, 4: 7.6, 91: 23.6}, dict[int, float])
+        self.check_immutable_fields_schema(app1, "Tuple1", ("a", "c"), ("a", "c"), tuple[str, ...])
+        self.check_immutable_fields_schema(app1, "FrozenSet1", frozenset({1, 2}), frozenset({1, 2}), frozenset[int])
+        self.check_immutable_fields_schema(app1, "Set1", frozenset({1, 2}), frozenset({1, 2}), set[int])
+
+        app2 = Appliance2()
+
+        self.immutable_vars__test_field(app2, "ListStr", ("mod val1", "mod val2"), ["val2", "val3"])
+        self.immutable_vars__test_field(app2, "Dict1", {4: 1.1, 9: 7.6, 51: 23.6}, {1: 1.1, 4: 7.6, 91: 23.6})
+        self.immutable_vars__test_field(app2, "Tuple1", ("aa", "cc"), ("h", "r"))
+        self.immutable_vars__test_field(app2, "FrozenSet1", frozenset({14, 27}), frozenset({4, 0}))
+        self.immutable_vars__test_field(app2, "Set1", frozenset({1, 20}), set({4, 0}))
+
+        self.check_immutable_fields_schema(app2, "ListStr", ("mod val1", "mod val2"), ("val1", "val2"), list[str])
+        self.check_immutable_fields_schema(app2, "Dict1", {4: 1.1, 9: 7.6, 51: 23.6}, {1: 1.1, 4: 7.6, 91: 23.6}, dict[int, float])
+        self.check_immutable_fields_schema(app2, "Tuple1", ("aa", "cc"), ("a", "c"), tuple[str, ...])
+        self.check_immutable_fields_schema(app2, "FrozenSet1", frozenset({14, 27}), frozenset({1, 2}), frozenset[int])
+        self.check_immutable_fields_schema(app2, "Set1", frozenset({1, 20}), frozenset({1, 2}), set[int])
+
+        self.immutable_vars__test_field(app1, "ListStr", ("val1", "val2"), ["val2", "val3"])
+        self.immutable_vars__test_field(app1, "Dict1", {1: 1.1, 4: 7.6, 91: 23.6}, {1: 1.1, 4: 7.6, 91: 23.6})
+        self.immutable_vars__test_field(app1, "Tuple1", ("a", "c"), ("h", "r"))
+        self.immutable_vars__test_field(app1, "FrozenSet1", frozenset({1, 2}), frozenset({4, 0}))
+        self.immutable_vars__test_field(app1, "Set1", frozenset({1, 2}), set({4, 0}))
+
+        self.check_immutable_fields_schema(app1, "ListStr", ("val1", "val2"), ("val1", "val2"), list[str])
+        self.check_immutable_fields_schema(app1, "Dict1", {1: 1.1, 4: 7.6, 91: 23.6}, {1: 1.1, 4: 7.6, 91: 23.6}, dict[int, float])
+        self.check_immutable_fields_schema(app1, "Tuple1", ("a", "c"), ("a", "c"), tuple[str, ...])
+        self.check_immutable_fields_schema(app1, "FrozenSet1", frozenset({1, 2}), frozenset({1, 2}), frozenset[int])
+        self.check_immutable_fields_schema(app1, "Set1", frozenset({1, 2}), frozenset({1, 2}), set[int])
+
+        # class can be created
+        class Appliance3(Appliance2):
+            ListStr2: list[str] = ["mod val3", "mod val3"]
+            Dict2: dict[int, float] = {9: 8.1, 5: 98.6, 551: 3.6}
+            Tuple2: "tuple[str,...]" = ("aaa", "ccc")
+            FrozenSet2: frozenset[int] = frozenset({114, 127})
+            Set2: set[int] = set({10, 250})
+
+        app3 = Appliance3()
+
+        self.immutable_vars__test_field(app3, "ListStr", ("mod val1", "mod val2"), ["val2", "val3"])
+        self.immutable_vars__test_field(app3, "Dict1", {4: 1.1, 9: 7.6, 51: 23.6}, {1: 1.1, 4: 7.6, 91: 23.6})
+        self.immutable_vars__test_field(app3, "Tuple1", ("aa", "cc"), ("h", "r"))
+        self.immutable_vars__test_field(app3, "FrozenSet1", frozenset({14, 27}), frozenset({4, 0}))
+        self.immutable_vars__test_field(app3, "Set1", frozenset({1, 20}), set({4, 0}))
+
+        self.immutable_vars__test_field(app3, "ListStr2", ("mod val3", "mod val3"), ["mod val3", "mod val3"])
+        self.immutable_vars__test_field(app3, "Dict2", {9: 8.1, 5: 98.6, 551: 3.6}, {9: 8.1, 5: 98.6, 551: 3.6})
+        self.immutable_vars__test_field(app3, "Tuple2", ("aaa", "ccc"), ("aaa", "ccc"))
+        self.immutable_vars__test_field(app3, "FrozenSet2", frozenset({114, 127}), frozenset({114, 127}))
+        self.immutable_vars__test_field(app3, "Set2", frozenset({10, 250}), set({10, 250}))
+
+        self.check_immutable_fields_schema(app3, "ListStr", ("mod val1", "mod val2"), ("val1", "val2"), list[str])
+        self.check_immutable_fields_schema(app3, "Dict1", {4: 1.1, 9: 7.6, 51: 23.6}, {1: 1.1, 4: 7.6, 91: 23.6}, dict[int, float])
+        self.check_immutable_fields_schema(app3, "Tuple1", ("aa", "cc"), ("a", "c"), tuple[str, ...])
+        self.check_immutable_fields_schema(app3, "FrozenSet1", frozenset({14, 27}), frozenset({1, 2}), frozenset[int])
+        self.check_immutable_fields_schema(app3, "Set1", frozenset({1, 20}), frozenset({1, 2}), set[int])
+
+        self.check_immutable_fields_schema(app3, "ListStr2", ("mod val3", "mod val3"), ("mod val3", "mod val3"), list[str])
+        self.check_immutable_fields_schema(app3, "Dict2", {9: 8.1, 5: 98.6, 551: 3.6}, {9: 8.1, 5: 98.6, 551: 3.6}, dict[int, float])
+        self.check_immutable_fields_schema(app3, "Tuple2", ("aaa", "ccc"), ("aaa", "ccc"), tuple[str, ...])
+        self.check_immutable_fields_schema(app3, "FrozenSet2", frozenset({114, 127}), frozenset({114, 127}), frozenset[int])
+        self.check_immutable_fields_schema(app3, "Set2", frozenset({10, 250}), frozenset({10, 250}), set[int])
+
+        self.immutable_vars__test_field(app2, "ListStr", ("mod val1", "mod val2"), ["val2", "val3"])
+        self.immutable_vars__test_field(app2, "Dict1", {4: 1.1, 9: 7.6, 51: 23.6}, {1: 1.1, 4: 7.6, 91: 23.6})
+        self.immutable_vars__test_field(app2, "Tuple1", ("aa", "cc"), ("h", "r"))
+        self.immutable_vars__test_field(app2, "FrozenSet1", frozenset({14, 27}), frozenset({4, 0}))
+        self.immutable_vars__test_field(app2, "Set1", frozenset({1, 20}), set({4, 0}))
+
+        self.check_immutable_fields_schema(app2, "ListStr", ("mod val1", "mod val2"), ("val1", "val2"), list[str])
+        self.check_immutable_fields_schema(app2, "Dict1", {4: 1.1, 9: 7.6, 51: 23.6}, {1: 1.1, 4: 7.6, 91: 23.6}, dict[int, float])
+        self.check_immutable_fields_schema(app2, "Tuple1", ("aa", "cc"), ("a", "c"), tuple[str, ...])
+        self.check_immutable_fields_schema(app2, "FrozenSet1", frozenset({14, 27}), frozenset({1, 2}), frozenset[int])
+        self.check_immutable_fields_schema(app2, "Set1", frozenset({1, 20}), frozenset({1, 2}), set[int])
+
+        self.immutable_vars__test_field(app1, "ListStr", ("val1", "val2"), ["val2", "val3"])
+        self.immutable_vars__test_field(app1, "Dict1", {1: 1.1, 4: 7.6, 91: 23.6}, {1: 1.1, 4: 7.6, 91: 23.6})
+        self.immutable_vars__test_field(app1, "Tuple1", ("a", "c"), ("h", "r"))
+        self.immutable_vars__test_field(app1, "FrozenSet1", frozenset({1, 2}), frozenset({4, 0}))
+        self.immutable_vars__test_field(app1, "Set1", frozenset({1, 2}), set({4, 0}))
+
+        self.check_immutable_fields_schema(app1, "ListStr", ("val1", "val2"), ("val1", "val2"), list[str])
+        self.check_immutable_fields_schema(app1, "Dict1", {1: 1.1, 4: 7.6, 91: 23.6}, {1: 1.1, 4: 7.6, 91: 23.6}, dict[int, float])
+        self.check_immutable_fields_schema(app1, "Tuple1", ("a", "c"), ("a", "c"), tuple[str, ...])
+        self.check_immutable_fields_schema(app1, "FrozenSet1", frozenset({1, 2}), frozenset({1, 2}), frozenset[int])
+        self.check_immutable_fields_schema(app1, "Set1", frozenset({1, 2}), frozenset({1, 2}), set[int])
+
+    def test_initializer(self):
+        """Testing first appliance level, and Field types (simple)"""
+
+        # class can be created
+        class Appliance1(dm.BaseAppliance):
+            VarInt: int = 12
+            VarInt2: int = 21
+            list1: list[int] = [1]
+            set1: set[float] = {1.43}
+            set2: set[float] = {5.43}
+            VarStr1: str = "abcd"
+
+            @classmethod
+            def __initializer(cls):
+
+                cls.VarInt2 = cls.VarInt + 1
+                cls.list1.append(2)
+                cls.set2 = cls.set1 | {1234}
+                cls.set1 = {0}
+                cls.VarStr1 = cls.VarStr1.upper()
+
+        app1 = Appliance1()
+
+        self.assertEqual(app1.VarInt, 12)
+        self.assertEqual(app1.VarInt2, 13)
+        self.assertEqual(app1.set1, frozenset({0}))
+        self.assertEqual(app1.set2, frozenset((1.43, 1234)))
+        self.assertEqual(app1.VarStr1, "ABCD")
+
+        # class can be created
+        class _(dm.BaseAppliance):
+            VarInt: int = 41
+
+            @classmethod
+            def __initializer(cls):
+
+                cls.VarInt = cls.VarInt + 1
+
+        app2 = _()
+        self.assertEqual(app2.VarInt, 42)
+
+    def test_initializer_safe(self):
+
+        with self.assertRaises(dm.ImportForbidden):
+
+            class test(dm.BaseAppliance):
+                _: int = 0
+
+                @classmethod
+                def __initializer(cls):
+                    import pprint
+
+        with self.assertRaises(NameError):
+
+            class _(dm.BaseAppliance):
+                _: int = 0
+
+                @classmethod
+                def __initializer(cls):
+                    eval("2 ** 8")
+
+        with self.assertRaises(NameError):
+
+            class _(dm.BaseAppliance):
+                _: int = 0
+
+                @classmethod
+                def __initializer(cls):
+                    open("foo")
+
+        with self.assertRaises(NameError):
+
+            class _(dm.BaseAppliance):
+                _: int = 0
+
+                @classmethod
+                def __initializer(cls):
+                    exec("exit()")
+
+        with self.assertRaises(NameError):
+
+            class _(dm.BaseAppliance):
+                _: int = 0
+
+                @classmethod
+                def __initializer(cls):
+                    compile("print(55)", "test", "eval")
+
+        with self.assertRaises(NameError):
+
+            class _(dm.BaseAppliance):
+                _: int = 0
+
+                @classmethod
+                def __initializer(cls):
+                    compile("print(55)", "test", "eval")
+
+        with self.assertRaises(dm.FunctionForbidden):
+
+            def testfc():
+                eval("print('test')")
+
+            class _(dm.BaseAppliance):
+                _: int = 0
+
+                @classmethod
+                def __initializer(cls):
+                    testfc()
+
+        # class can be created
+        class Appliance2(dm.BaseAppliance):
+            VarInt: int = -56
+            VarInt2: int = 0
+            VarInt3: int = 0
+            VarInt4: int = 0
+            VarInt5: int = 0
+            VarFloat: float = 1.23
+            list1: list[int] = [1, 2, 0, 4]
+            list2: Optional[list[int]] = None
+            list3: Optional[list[int]] = None
+            set1: set[float] = {1.43}
+            set2: set[float] = {5.43}
+
+            @classmethod
+            def __initializer(cls):
+                cls.VarInt2 = abs(cls.VarInt)
+                cls.VarFloat = round(cls.VarFloat)
+                cls.VarInt = min(cls.list1)
+                cls.VarInt3 = max(cls.list1)
+                cls.VarInt4 = sum(cls.list1)
+                cls.VarInt5 = len(cls.list1)
+                cls.list2 = sorted(cls.list1)
+                cls.list3 = []
+                for i in range(5):
+                    cls.list3.append(i)
+                cls.set2 = {math.ceil(list(cls.set1)[0])}
+
+        app2 = Appliance2()
+        self.assertEqual(app2.VarInt2, 56)
+        self.assertEqual(app2.VarFloat, 1)
+        self.assertEqual(app2.VarInt, 0)
+        self.assertEqual(app2.VarInt3, 4)
+        self.assertEqual(app2.VarInt4, 7)
+        self.assertEqual(app2.VarInt5, 4)
+        self.assertEqual(app2.list2, (0, 1, 2, 4))
+        self.assertEqual(app2.list3, (0, 1, 2, 3, 4))
+        self.assertEqual(app2.set2, {2})
+
+        with self.assertRaises(NameError):
+
+            class _(dm.BaseAppliance):
+                _: int = 0
+
+                @classmethod
+                def __initializer(cls):
+                    test_initializer_safe_testfc()
+
 
 # ---------- main ----------