Add non-Path files support (for example Traversable) and open files using Path.open method (#724)

Author: mahenzon

pydantic_settings/sources/base.py

@@ -3,8 +3,8 @@
 from __future__ import annotations as _annotations
 
 import json
-import os
 from abc import ABC, abstractmethod
+from collections.abc import Sequence
 from dataclasses import asdict, is_dataclass
 from pathlib import Path
 from typing import TYPE_CHECKING, Any, cast, get_args
@@ -196,11 +196,17 @@ class ConfigFileSourceMixin(ABC):
     def _read_files(self, files: PathType | None, deep_merge: bool = False) -> dict[str, Any]:
         if files is None:
             return {}
-        if isinstance(files, (str, os.PathLike)):
+        if not isinstance(files, Sequence) or isinstance(files, str):
             files = [files]
         vars: dict[str, Any] = {}
         for file in files:
-            file_path = Path(file).expanduser()
+            if isinstance(file, str):
+                file_path = Path(file)
+            else:
+                file_path = file
+            if isinstance(file_path, Path):
+                file_path = file_path.expanduser()
+
             if not file_path.is_file():
                 continue
 

pydantic_settings/sources/providers/json.py

@@ -38,7 +38,7 @@ def __init__(
         super().__init__(settings_cls, self.json_data)
 
     def _read_file(self, file_path: Path) -> dict[str, Any]:
-        with open(file_path, encoding=self.json_file_encoding) as json_file:
+        with file_path.open(encoding=self.json_file_encoding) as json_file:
             return json.load(json_file)
 
     def __repr__(self) -> str:

pydantic_settings/sources/providers/toml.py

@@ -58,7 +58,7 @@ def __init__(
 
     def _read_file(self, file_path: Path) -> dict[str, Any]:
         import_toml()
-        with open(file_path, mode='rb') as toml_file:
+        with file_path.open(mode='rb') as toml_file:
             if sys.version_info < (3, 11):
                 return tomli.load(toml_file)
             return tomllib.load(toml_file)

pydantic_settings/sources/providers/yaml.py

@@ -66,7 +66,7 @@ def __init__(
 
     def _read_file(self, file_path: Path) -> dict[str, Any]:
         import_yaml()
-        with open(file_path, encoding=self.yaml_file_encoding) as yaml_file:
+        with file_path.open(encoding=self.yaml_file_encoding) as yaml_file:
             return yaml.safe_load(yaml_file) or {}
 
     def __repr__(self) -> str:

tests/test_source_json.py

@@ -2,7 +2,15 @@
 Test pydantic_settings.JsonConfigSettingsSource.
 """
 
+import importlib.resources
 import json
+import sys
+
+if sys.version_info < (3, 11):
+    from importlib.abc import Traversable
+else:
+    from importlib.resources.abc import Traversable
+
 from pathlib import Path
 
 import pytest
@@ -132,3 +140,77 @@ def settings_customise_sources(
 
     s = Settings()
     assert s.model_dump() == {'hello': 'world', 'nested': {'foo': 3, 'bar': 2 if deep_merge else 0}}
+
+
+class TestTraversableSupport:
+    FILENAME = 'example_test_config.json'
+
+    @pytest.fixture(params=['importlib_resources', 'custom'])
+    def json_config_path(self, request, tmp_path):
+        tests_package_dir = importlib.resources.files('tests')
+
+        if request.param == 'importlib_resources':
+            # get Traversable object using importlib.resources
+            return tests_package_dir / self.FILENAME
+
+        # Create a custom Traversable implementation
+        class CustomTraversable(Traversable):
+            def __init__(self, path):
+                self._path = path
+
+            def __truediv__(self, child):
+                return CustomTraversable(self._path / child)
+
+            def is_file(self):
+                return self._path.is_file()
+
+            def is_dir(self):
+                return self._path.is_dir()
+
+            def iterdir(self):
+                raise NotImplementedError('iterdir not implemented for this test')
+
+            def open(self, mode='r', *args, **kwargs):
+                return self._path.open(mode, *args, **kwargs)
+
+            def read_bytes(self):
+                return self._path.read_bytes()
+
+            def read_text(self, encoding=None):
+                return self._path.read_text(encoding=encoding)
+
+            @property
+            def name(self):
+                return self._path.name
+
+            def joinpath(self, *descendants):
+                return CustomTraversable(self._path.joinpath(*descendants))
+
+        custom_traversable = CustomTraversable(tests_package_dir)
+        return custom_traversable / self.FILENAME
+
+    def test_traversable_support(self, json_config_path: Traversable):
+        assert json_config_path.is_file()
+
+        class Settings(BaseSettings):
+            foobar: str
+
+            model_config = SettingsConfigDict(
+                # Traversable is not added in annotation, but is supported
+                json_file=json_config_path,
+            )
+
+            @classmethod
+            def settings_customise_sources(
+                cls,
+                settings_cls: type[BaseSettings],
+                init_settings: PydanticBaseSettingsSource,
+                env_settings: PydanticBaseSettingsSource,
+                dotenv_settings: PydanticBaseSettingsSource,
+                file_secret_settings: PydanticBaseSettingsSource,
+            ) -> tuple[PydanticBaseSettingsSource, ...]:
+                return (JsonConfigSettingsSource(settings_cls),)
+
+        s = Settings()
+        # "test" value in file
+        assert s.foobar == 'test'