bpo-42129: Add support for resources in namespaces (GH-24670)
* Unify behavior in ResourceReaderDefaultsTests and align with the behavior found in importlib_resources.
* Equip NamespaceLoader with a NamespaceReader.
* Apply changes from importlib_resources 5.0.4
diff --git a/Lib/importlib/resources.py b/Lib/importlib/resources.py
index 4169171..db0e0c0 100644
--- a/Lib/importlib/resources.py
+++ b/Lib/importlib/resources.py
@@ -3,8 +3,10 @@
from . import _common
from ._common import as_file, files
+from .abc import ResourceReader
from contextlib import suppress
from importlib.abc import ResourceLoader
+from importlib.machinery import ModuleSpec
from io import BytesIO, TextIOWrapper
from pathlib import Path
from types import ModuleType
@@ -18,6 +20,7 @@
__all__ = [
'Package',
'Resource',
+ 'ResourceReader',
'as_file',
'contents',
'files',
@@ -27,7 +30,7 @@
'path',
'read_binary',
'read_text',
- ]
+]
Package = Union[str, ModuleType]
@@ -41,36 +44,45 @@ def open_binary(package: Package, resource: Resource) -> BinaryIO:
reader = _common.get_resource_reader(package)
if reader is not None:
return reader.open_resource(resource)
- absolute_package_path = os.path.abspath(
- package.__spec__.origin or 'non-existent file')
- package_path = os.path.dirname(absolute_package_path)
- full_path = os.path.join(package_path, resource)
- try:
- return open(full_path, mode='rb')
- except OSError:
- # Just assume the loader is a resource loader; all the relevant
- # importlib.machinery loaders are and an AttributeError for
- # get_data() will make it clear what is needed from the loader.
- loader = cast(ResourceLoader, package.__spec__.loader)
- data = None
- if hasattr(package.__spec__.loader, 'get_data'):
- with suppress(OSError):
- data = loader.get_data(full_path)
- if data is None:
- package_name = package.__spec__.name
- message = '{!r} resource not found in {!r}'.format(
- resource, package_name)
- raise FileNotFoundError(message)
- return BytesIO(data)
+ spec = cast(ModuleSpec, package.__spec__)
+ # Using pathlib doesn't work well here due to the lack of 'strict'
+ # argument for pathlib.Path.resolve() prior to Python 3.6.
+ if spec.submodule_search_locations is not None:
+ paths = spec.submodule_search_locations
+ elif spec.origin is not None:
+ paths = [os.path.dirname(os.path.abspath(spec.origin))]
+
+ for package_path in paths:
+ full_path = os.path.join(package_path, resource)
+ try:
+ return open(full_path, mode='rb')
+ except OSError:
+ # Just assume the loader is a resource loader; all the relevant
+ # importlib.machinery loaders are and an AttributeError for
+ # get_data() will make it clear what is needed from the loader.
+ loader = cast(ResourceLoader, spec.loader)
+ data = None
+ if hasattr(spec.loader, 'get_data'):
+ with suppress(OSError):
+ data = loader.get_data(full_path)
+ if data is not None:
+ return BytesIO(data)
+
+ raise FileNotFoundError(
+ '{!r} resource not found in {!r}'.format(resource, spec.name)
+ )
-def open_text(package: Package,
- resource: Resource,
- encoding: str = 'utf-8',
- errors: str = 'strict') -> TextIO:
+def open_text(
+ package: Package,
+ resource: Resource,
+ encoding: str = 'utf-8',
+ errors: str = 'strict',
+) -> TextIO:
"""Return a file-like object opened for text reading of the resource."""
return TextIOWrapper(
- open_binary(package, resource), encoding=encoding, errors=errors)
+ open_binary(package, resource), encoding=encoding, errors=errors
+ )
def read_binary(package: Package, resource: Resource) -> bytes:
@@ -79,10 +91,12 @@ def read_binary(package: Package, resource: Resource) -> bytes:
return fp.read()
-def read_text(package: Package,
- resource: Resource,
- encoding: str = 'utf-8',
- errors: str = 'strict') -> str:
+def read_text(
+ package: Package,
+ resource: Resource,
+ encoding: str = 'utf-8',
+ errors: str = 'strict',
+) -> str:
"""Return the decoded string of the resource.
The decoding-related arguments have the same semantics as those of
@@ -93,8 +107,9 @@ def read_text(package: Package,
def path(
- package: Package, resource: Resource,
- ) -> 'ContextManager[Path]':
+ package: Package,
+ resource: Resource,
+) -> 'ContextManager[Path]':
"""A context manager providing a file path object to the resource.
If the resource does not already exist on its own on the file system,
@@ -106,15 +121,17 @@ def path(
reader = _common.get_resource_reader(_common.get_package(package))
return (
_path_from_reader(reader, _common.normalize_path(resource))
- if reader else
- _common.as_file(
- _common.files(package).joinpath(_common.normalize_path(resource)))
+ if reader
+ else _common.as_file(
+ _common.files(package).joinpath(_common.normalize_path(resource))
)
+ )
def _path_from_reader(reader, resource):
- return _path_from_resource_path(reader, resource) or \
- _path_from_open_resource(reader, resource)
+ return _path_from_resource_path(reader, resource) or _path_from_open_resource(
+ reader, resource
+ )
def _path_from_resource_path(reader, resource):
@@ -154,15 +171,10 @@ def contents(package: Package) -> Iterable[str]:
reader = _common.get_resource_reader(package)
if reader is not None:
return _ensure_sequence(reader.contents())
- # Is the package a namespace package? By definition, namespace packages
- # cannot have resources.
- namespace = (
- package.__spec__.origin is None or
- package.__spec__.origin == 'namespace'
- )
- if namespace or not package.__spec__.has_location:
- return ()
- return list(item.name for item in _common.from_package(package).iterdir())
+ transversable = _common.from_package(package)
+ if transversable.is_dir():
+ return list(item.name for item in transversable.iterdir())
+ return []
@singledispatch