Move compatibility and future behaviors into separate packages.

Author: jaraco

importlib_resources/_common.py

@@ -12,7 +12,7 @@
 from typing import Union, Optional, cast
 from .abc import ResourceReader, Traversable
 
-from ._compat import wrap_spec
+from .future.adapters import wrap_spec
 
 Package = Union[types.ModuleType, str]
 Anchor = Package

importlib_resources/abc.py

@@ -3,8 +3,9 @@
 import itertools
 import pathlib
 from typing import Any, BinaryIO, Iterable, Iterator, NoReturn, Text, Optional
+from typing import runtime_checkable, Protocol
 
-from ._compat import runtime_checkable, Protocol, StrPath
+from .compat.py38 import StrPath
 
 
 __all__ = ["ResourceReader", "Traversable", "TraversableResources"]

importlib_resources/compat/__init__.py

@@ -0,0 +1,11 @@
+import os
+import sys
+
+from typing import Union
+
+
+if sys.version_info >= (3, 9):
+    StrPath = Union[str, os.PathLike[str]]
+else:
+    # PathLike is only subscriptable at runtime in 3.9+
+    StrPath = Union[str, "os.PathLike[str]"]

importlib_resources/compat/py38.py

@@ -0,0 +1,10 @@
+import sys
+
+
+__all__ = ['ZipPath']
+
+
+if sys.version_info >= (3, 10):
+    from zipfile import Path as ZipPath  # type: ignore
+else:
+    from zipp import Path as ZipPath  # type: ignore

importlib_resources/compat/py39.py

@@ -8,25 +8,7 @@
 from contextlib import suppress
 from typing import Union
 
-
-if sys.version_info >= (3, 10):
-    from zipfile import Path as ZipPath  # type: ignore
-else:
-    from zipp import Path as ZipPath  # type: ignore
-
-
-try:
-    from typing import runtime_checkable  # type: ignore
-except ImportError:
-
-    def runtime_checkable(cls):  # type: ignore
-        return cls
-
-
-try:
-    from typing import Protocol  # type: ignore
-except ImportError:
-    Protocol = abc.ABC  # type: ignore
+from .. import readers, _adapters
 
 
 class TraversableResourcesLoader:
@@ -46,8 +28,6 @@ def path(self):
         return self.spec.origin
 
     def get_resource_reader(self, name):
-        from . import readers, _adapters
-
         def _zip_reader(spec):
             with suppress(AttributeError):
                 return readers.ZipReader(spec.loader, spec.name)
@@ -98,13 +78,4 @@ def wrap_spec(package):
     Supersedes _adapters.wrap_spec to use TraversableResourcesLoader
     from above for older Python compatibility (<3.10).
     """
-    from . import _adapters
-
     return _adapters.SpecLoaderAdapter(package.__spec__, TraversableResourcesLoader)
-
-
-if sys.version_info >= (3, 9):
-    StrPath = Union[str, os.PathLike[str]]
-else:
-    # PathLike is only subscriptable at runtime in 3.9+
-    StrPath = Union[str, "os.PathLike[str]"]

importlib_resources/future/__init__.py

@@ -9,7 +9,7 @@
 from . import abc
 
 from ._itertools import only
-from ._compat import ZipPath
+from .compat.py39 import ZipPath
 
 
 def remove_duplicates(items):