Remove attrs dependency and use pydantic instead (#168)

Co-authored-by: konstantin <konstantin.klein@hochfrequenz.de>

requirements.in

@@ -1,4 +1,3 @@
-attrs
 bo4e>=0.5.0
 pydantic>=2.0.0
 typeguard

requirements.txt

@@ -6,8 +6,6 @@
 #
 annotated-types==0.5.0
     # via pydantic
-attrs==23.2.0
-    # via -r requirements.in
 bidict==0.22.1
     # via
     #   -r requirements.in

setup.cfg

@@ -32,7 +32,6 @@ zip_safe = False
 include_package_data = True
 python_requires = >=3.10
 install_requires =
-    attrs
     bo4e
     pydantic>=2.0.0
     typeguard>=4.0.1

src/bomf/loader/entityloader.py

@@ -9,63 +9,56 @@
 from pathlib import Path
 from typing import Awaitable, Callable, Generic, Optional, TypeVar
 
-import attrs
 from generics import get_filled_type
-from pydantic import BaseModel, TypeAdapter, ValidationError  # pylint:disable=no-name-in-module
+from pydantic import BaseModel, TypeAdapter, ConfigDict, ValidationError  # pylint:disable=no-name-in-module
 
 _TargetEntity = TypeVar("_TargetEntity")
 
 
-@attrs.define(auto_attribs=True, kw_only=True)
-class EntityLoadingResult:  # pylint:disable=too-few-public-methods
+class EntityLoadingResult(BaseModel):  # pylint:disable=too-few-public-methods
     """
     Information gathered while loading a _TargetEntity into the target system.
     """
 
-    id_in_target_system: Optional[str] = attrs.field(
-        validator=attrs.validators.optional(attrs.validators.instance_of(str)), default=None
-    )
+    model_config = ConfigDict(arbitrary_types_allowed=True)
+
+    id_in_target_system: Optional[str] = None
     """
     the optional ID of the entity in the target system (e.g. if a new (GU)ID is generated upon loading)
     """
-    polling_task: Optional[Awaitable] = attrs.field(default=None)
+    polling_task: Optional[Awaitable] = None
     """
     If this task is awaited it means, that the target system is done with processing the request.
     A possible use case is that the target system responds with something like an event ID which can be used to poll
     an endpoint until it returns the expected result.
     """
 
 
-@attrs.define(auto_attribs=True, kw_only=True)
-class LoadingSummary(ABC, Generic[_TargetEntity]):  # pylint:disable=too-few-public-methods
+class LoadingSummary(BaseModel, ABC, Generic[_TargetEntity]):  # pylint:disable=too-few-public-methods
     """
     Each instance of _TargetEntity that is loaded to the target system results in a LoadingSummary.
     It is a summary that reports to calling code.
     """
 
-    was_loaded_successfully: bool = attrs.field(validator=attrs.validators.instance_of(bool))
+    model_config = ConfigDict(arbitrary_types_allowed=True)
+
+    was_loaded_successfully: bool
     """
     true iff the instance has been loaded successfully
     """
-    loaded_at: Optional[datetime] = attrs.field(
-        validator=attrs.validators.optional(attrs.validators.instance_of(datetime)), default=None
-    )
+    loaded_at: Optional[datetime] = None
     """
     point in time at which the loading (without verification) has completed; if not None
     """
-    verified_at: Optional[datetime] = attrs.field(
-        validator=attrs.validators.optional(attrs.validators.instance_of(datetime)), default=None
-    )
+    verified_at: Optional[datetime] = None
     """
     point in time at which the loading of this entity has been verified (or None if not)
     """
-    id_in_target_system: Optional[str] = attrs.field(
-        validator=attrs.validators.optional(attrs.validators.instance_of(str)), default=None
-    )
+    id_in_target_system: Optional[str] = None
     """
     the optional ID of the entity in the target system (e.g. if a new (GU)ID is generated upon loading)
     """
-    loading_error: Optional[Exception] = attrs.field(default=None)
+    loading_error: Optional[Exception] = None
 
 
 class EntityLoader(ABC, Generic[_TargetEntity]):  # pylint:disable=too-few-public-methods

src/bomf/model/__init__.py

@@ -7,7 +7,6 @@
 from abc import ABC
 from typing import TypeVar, Union
 
-import attrs
 from bo4e.bo.geschaeftsobjekt import Geschaeftsobjekt
 from bo4e.com.com import COM
 from pydantic import BaseModel, Field  # pylint: disable=no-name-in-module
@@ -26,8 +25,7 @@
 
 
 # pylint:disable=too-few-public-methods
-@attrs.define(kw_only=True, auto_attribs=True)
-class BusinessObjectRelation:
+class BusinessObjectRelation(BaseModel):
     """
     A business object relation describes the relation between two business object.
     E.g. a relation could have the type "has_melo" where relation_part_a is a bo4e.bo.Vertrag
@@ -37,7 +35,7 @@ class BusinessObjectRelation:
     necessary relation information.
     """
 
-    relation_type: enum.Enum = attrs.field()
+    relation_type: enum.Enum
     """
     The relation type describes how two business objects relate to each other.
     This is not (only) about cardinality. It's about being able to model different relations between objects.
@@ -48,12 +46,12 @@ class BusinessObjectRelation:
     All these relation types are 1:1 relations between business partners and adresses, yet they all carry different
     meaning which we'd like to distinguish in our data.
     """
-    relation_part_a: Bo4eTyp = attrs.field()
+    relation_part_a: Bo4eTyp
     """
     one Business Object or COM
     """
 
-    relation_part_b: Bo4eTyp = attrs.field()
+    relation_part_b: Bo4eTyp
     """
     another Business Object or COM
     """

unittests/test_mapper.py

@@ -1,6 +1,6 @@
 from typing import Optional, Type
 
-import attrs
+from pydantic import BaseModel
 import pytest  # type:ignore[import]
 from bo4e.bo.marktlokation import Marktlokation
 from bo4e.bo.messlokation import Messlokation
@@ -15,10 +15,9 @@ class _NotImplementedBo4eDataSetMixin:
     """
 
 
-@attrs.define(kw_only=True, auto_attribs=True)
-class _MaLoAndMeLo(_NotImplementedBo4eDataSetMixin):
-    malo: Marktlokation = attrs.field()
-    melo: Messlokation = attrs.field()
+class _MaLoAndMeLo(BaseModel, _NotImplementedBo4eDataSetMixin):
+    malo: Marktlokation
+    melo: Messlokation
 
     def get_business_object(self, bo_type: Type[Bo4eTyp], specification: Optional[str] = None) -> Bo4eTyp:
         # pyling:disable=fixme