Requirements: Bump Pydantic from 1.8 to 2.0.2.

[ohadbenita]

This change comes to solve issues with depending projects that want to bump Pydantic's version but are unable to do so because of aws-sam-translator's dependency version.

[hoffa]

Similar request in aws/aws-sam-cli#5456 (review)

However need to fix the breaking changes.

[leandrodamascena]

Is the idea here to drop support for Pydanticv1 and just keep support for v2? Are there any plans to keep being able to use both versions? I ask this because there are systems that use Pydanticv1 and are not yet ready to upgrade to v2 and this library can be a transitive dependency that will cause problems if it only supports v2.

[hoffa]

@leandrodamascena There's no immediate plans or need to switch. Supporting both major versions incurs engineering costs, but until someone actually goes through the (hopefully minor) effort of upgrading, it'll be hard to determine whether it makes sense to maintain both for some time.

[yan12125]

pydantic 2 comes with a v1 module for compatibility, so I can do something like this to support both major versions:

diff --git requirements/base.txt requirements/base.txt
index 4a1af3f7..8fb12685 100755
--- requirements/base.txt
+++ requirements/base.txt
@@ -3,4 +3,4 @@ jsonschema<5,>=3.2  # TODO: evaluate risk of removing jsonschema 3.x support
 typing_extensions>=4.4,<5 # 3.7 doesn't have Literal
 
 # resource validation & schema generation
-pydantic~=1.8
+pydantic>=1.8
diff --git samtranslator/compat.py samtranslator/compat.py
new file mode 100644
index 00000000..7f913f0d
--- /dev/null
+++ samtranslator/compat.py
@@ -0,0 +1,4 @@
+try:
+    from pydantic import v1 as pydantic
+except ImportError:
+    import pydantic
diff --git samtranslator/internal/schema_source/any_cfn_resource.py samtranslator/internal/schema_source/any_cfn_resource.py
index 08f78fcb..a13b3741 100644
--- samtranslator/internal/schema_source/any_cfn_resource.py
+++ samtranslator/internal/schema_source/any_cfn_resource.py
@@ -1,4 +1,4 @@
-import pydantic
+from samtranslator.compat import pydantic
 
 from samtranslator.internal.schema_source.common import LenientBaseModel
 
diff --git samtranslator/internal/schema_source/common.py samtranslator/internal/schema_source/common.py
index 66fc77d7..ed1ed5b2 100644
--- samtranslator/internal/schema_source/common.py
+++ samtranslator/internal/schema_source/common.py
@@ -3,11 +3,10 @@ from functools import partial
 from pathlib import Path
 from typing import Any, Dict, List, Optional, TypeVar, Union
 
-import pydantic
-from pydantic import Extra, Field
 from typing_extensions import Literal
 
 from samtranslator.model.types import PassThrough
+from samtranslator.compat import pydantic
 
 
 # If using PassThrough as-is, pydantic will mark the field as not required:
@@ -53,7 +52,7 @@ def passthrough_prop(sam_docs_stem: str, sam_docs_name: str, prop_path: List[str
     for s in prop_path[1:]:
         path.extend(["properties", s])
     docs = _DOCS["properties"][sam_docs_stem][sam_docs_name]
-    return Field(
+    return pydantic.Field(
         title=sam_docs_name,
         # We add a custom value to the schema containing the path to the pass-through
         # documentation; the dict containing the value is replaced in the final schema
@@ -68,7 +67,7 @@ def passthrough_prop(sam_docs_stem: str, sam_docs_name: str, prop_path: List[str
 
 def _get_prop(stem: str, name: str) -> Any:
     docs = _DOCS["properties"][stem][name]
-    return Field(
+    return pydantic.Field(
         title=name,
         # https://code.visualstudio.com/docs/languages/json#_use-rich-formatting-in-hovers
         markdownDescription=docs,
@@ -78,7 +77,7 @@ def _get_prop(stem: str, name: str) -> Any:
 # By default strict: https://pydantic-docs.helpmanual.io/usage/model_config/#change-behaviour-globally
 class BaseModel(LenientBaseModel):
     class Config:
-        extra = Extra.forbid
+        extra = pydantic.Extra.forbid
 
     def __getattribute__(self, __name: str) -> Any:
         """Overloading get attribute operation to allow access PassThroughProp without using __root__"""
diff --git samtranslator/internal/schema_source/schema.py samtranslator/internal/schema_source/schema.py
index 6550c407..1e3cd1f8 100644
--- samtranslator/internal/schema_source/schema.py
+++ samtranslator/internal/schema_source/schema.py
@@ -6,7 +6,7 @@ from copy import deepcopy
 from pathlib import Path
 from typing import Any, Callable, Dict, List, Optional, Type, Union
 
-import pydantic
+from samtranslator.compat import pydantic
 
 from samtranslator.internal.schema_source import (
     any_cfn_resource,
diff --git samtranslator/model/__init__.py samtranslator/model/__init__.py
index 77748744..9cffffbc 100644
--- samtranslator/model/__init__.py
+++ samtranslator/model/__init__.py
@@ -5,8 +5,7 @@ from abc import ABC, ABCMeta, abstractmethod
 from contextlib import suppress
 from typing import Any, Callable, Dict, List, Optional, Tuple, Type, TypeVar
 
-from pydantic import BaseModel
-from pydantic.error_wrappers import ValidationError
+from samtranslator.compat import pydantic
 
 from samtranslator.model.exceptions import (
     ExpectedType,
@@ -17,7 +16,7 @@ from samtranslator.model.tags.resource_tagging import get_tag_list
 from samtranslator.model.types import IS_DICT, IS_STR, PassThrough, Validator, any_type, is_type
 from samtranslator.plugins import LifeCycleEvents
 
-RT = TypeVar("RT", bound=BaseModel)  # return type
+RT = TypeVar("RT", bound=pydantic.BaseModel)  # return type
 
 
 class PropertyType:
@@ -348,7 +347,7 @@ class Resource(ABC):
         """
         try:
             return cls.parse_obj(self._generate_resource_dict()["Properties"])
-        except ValidationError as e:
+        except pydantic.error_wrappers.ValidationError as e:
             error_properties: str = ""
             with suppress(KeyError):
                 error_properties = ".".join(str(x) for x in e.errors()[0]["loc"])

Tests pass with pydantic 1.10.9 and 2.0.2.

Update 2023/07/15: add a forgotten file to the patch

[yan12125]

Hi, is there a further plan for Pydantic 2.x support? From my testing above, the burden to support both 1.x and 2.x seems acceptable.

[ConnorRobertson]

Could you open up a new PR with your changes? @yan12125

[yan12125]

Sure, here you go: #3282