fix: support properly path type (#2801)

* feat: add `StrPath` type

* fix: support properly path type

* add test

* fix: merge

* remove useless if statement

* fix: cython

Co-authored-by: PrettyWood <em.jolibois@gmail.com>

pydantic/env_settings.py

@@ -6,7 +6,7 @@ from typing import AbstractSet, Any, Callable, Dict, List, Mapping, Optional, Tu
 from .config import BaseConfig, Extra
 from .fields import ModelField
 from .main import BaseModel
-from .typing import display_as_type
+from .typing import StrPath, display_as_type
 from .utils import deep_update, path_type, sequence_like
 
 env_file_sentinel = str(object())
@@ -28,9 +28,9 @@ class BaseSettings(BaseModel):
 
     def __init__(
         __pydantic_self__,
-        _env_file: Union[Path, str, None] = env_file_sentinel,
+        _env_file: Optional[StrPath] = env_file_sentinel,
         _env_file_encoding: Optional[str] = None,
-        _secrets_dir: Union[Path, str, None] = None,
+        _secrets_dir: Optional[StrPath] = None,
         **values: Any,
     ) -> None:
         # Uses something other than `self` the first arg to allow "self" as a settable attribute
@@ -43,9 +43,9 @@ class BaseSettings(BaseModel):
     def _build_values(
         self,
         init_kwargs: Dict[str, Any],
-        _env_file: Union[Path, str, None] = None,
+        _env_file: Optional[StrPath] = None,
         _env_file_encoding: Optional[str] = None,
-        _secrets_dir: Union[Path, str, None] = None,
+        _secrets_dir: Optional[StrPath] = None,
     ) -> Dict[str, Any]:
         # Configure built-in sources
         init_settings = InitSettingsSource(init_kwargs=init_kwargs)
@@ -133,8 +133,8 @@ class InitSettingsSource:
 class EnvSettingsSource:
     __slots__ = ('env_file', 'env_file_encoding')
 
-    def __init__(self, env_file: Union[Path, str, None], env_file_encoding: Optional[str]):
-        self.env_file: Union[Path, str, None] = env_file
+    def __init__(self, env_file: Optional[StrPath], env_file_encoding: Optional[str]):
+        self.env_file: Optional[StrPath] = env_file
         self.env_file_encoding: Optional[str] = env_file_encoding
 
     def __call__(self, settings: BaseSettings) -> Dict[str, Any]:
@@ -183,8 +183,8 @@ class EnvSettingsSource:
 class SecretsSettingsSource:
     __slots__ = ('secrets_dir',)
 
-    def __init__(self, secrets_dir: Union[Path, str, None]):
-        self.secrets_dir: Union[Path, str, None] = secrets_dir
+    def __init__(self, secrets_dir: Optional[StrPath]):
+        self.secrets_dir: Optional[StrPath] = secrets_dir
 
     def __call__(self, settings: BaseSettings) -> Dict[str, Any]:
         """
@@ -221,7 +221,9 @@ class SecretsSettingsSource:
         return f'SecretsSettingsSource(secrets_dir={self.secrets_dir!r})'
 
 
-def read_env_file(file_path: Path, *, encoding: str = None, case_sensitive: bool = False) -> Dict[str, Optional[str]]:
+def read_env_file(
+    file_path: StrPath, *, encoding: str = None, case_sensitive: bool = False
+) -> Dict[str, Optional[str]]:
     try:
         from dotenv import dotenv_values
     except ImportError as e:

pydantic/typing.py

@@ -1,4 +1,5 @@
 import sys
+from os import PathLike
 from typing import (  # type: ignore
     TYPE_CHECKING,
     AbstractSet,
@@ -206,6 +207,17 @@ else:
     WithArgsTypes = (typing._GenericAlias, types.GenericAlias, types.UnionType)
 
 
+if sys.version_info < (3, 9):
+    StrPath = Union[str, PathLike]
+else:
+    StrPath = Union[str, PathLike]
+    # TODO: Once we switch to Cython 3 to handle generics properly
+    #  (https://github.com/cython/cython/issues/2753), use following lines instead
+    #  of the one above
+    # # os.PathLike only becomes subscriptable from Python 3.9 onwards
+    # StrPath = Union[str, PathLike[str]]
+
+
 if TYPE_CHECKING:
     from .fields import ModelField
 
@@ -256,6 +268,7 @@ __all__ = (
     'typing_base',
     'get_all_type_hints',
     'is_union_origin',
+    'StrPath',
 )
 
 

tests/mypy/modules/success.py

@@ -4,9 +4,10 @@ Test pydantic's compliance with mypy.
 Do a little skipping about with types to demonstrate its usage.
 """
 import json
+import os
 import sys
 from datetime import date, datetime, timedelta
-from pathlib import Path
+from pathlib import Path, PurePath
 from typing import Any, Dict, Generic, List, Optional, TypeVar
 from uuid import UUID
 
@@ -14,6 +15,7 @@ from pydantic import (
     UUID1,
     BaseConfig,
     BaseModel,
+    BaseSettings,
     DirectoryPath,
     Extra,
     FilePath,
@@ -250,3 +252,20 @@ class Config(BaseConfig):
     title = 'Record'
     extra = Extra.ignore
     max_anystr_length = 1234
+
+
+class Settings(BaseSettings):
+    ...
+
+
+class CustomPath(PurePath):
+    def __init__(self, *args: str):
+        self.path = os.path.join(*args)
+
+    def __fspath__(self) -> str:
+        return f'a/custom/{self.path}'
+
+
+def dont_check_path_existence() -> None:
+    Settings(_env_file='a/path', _secrets_dir='a/path')
+    Settings(_env_file=CustomPath('a/path'), _secrets_dir=CustomPath('a/path'))