AlkantarClanX12
Current Path : /lib64/python3.8/importlib/ |
Current File : //lib64/python3.8/importlib/resources.py |
import os import tempfile from . import abc as resources_abc from contextlib import contextmanager, suppress from importlib import import_module from importlib.abc import ResourceLoader from io import BytesIO, TextIOWrapper from pathlib import Path from types import ModuleType from typing import Iterable, Iterator, Optional, Set, Union # noqa: F401 from typing import cast from typing.io import BinaryIO, TextIO from zipimport import ZipImportError __all__ = [ 'Package', 'Resource', 'contents', 'is_resource', 'open_binary', 'open_text', 'path', 'read_binary', 'read_text', ] Package = Union[str, ModuleType] Resource = Union[str, os.PathLike] def _get_package(package) -> ModuleType: """Take a package name or module object and return the module. If a name, the module is imported. If the passed or imported module object is not a package, raise an exception. """ if hasattr(package, '__spec__'): if package.__spec__.submodule_search_locations is None: raise TypeError('{!r} is not a package'.format( package.__spec__.name)) else: return package else: module = import_module(package) if module.__spec__.submodule_search_locations is None: raise TypeError('{!r} is not a package'.format(package)) else: return module def _normalize_path(path) -> str: """Normalize a path by ensuring it is a string. If the resulting string contains path separators, an exception is raised. """ parent, file_name = os.path.split(path) if parent: raise ValueError('{!r} must be only a file name'.format(path)) else: return file_name def _get_resource_reader( package: ModuleType) -> Optional[resources_abc.ResourceReader]: # Return the package's loader if it's a ResourceReader. We can't use # a issubclass() check here because apparently abc.'s __subclasscheck__() # hook wants to create a weak reference to the object, but # zipimport.zipimporter does not support weak references, resulting in a # TypeError. That seems terrible. spec = package.__spec__ if hasattr(spec.loader, 'get_resource_reader'): return cast(resources_abc.ResourceReader, spec.loader.get_resource_reader(spec.name)) return None def _check_location(package): if package.__spec__.origin is None or not package.__spec__.has_location: raise FileNotFoundError(f'Package has no location {package!r}') def open_binary(package: Package, resource: Resource) -> BinaryIO: """Return a file-like object opened for binary reading of the resource.""" resource = _normalize_path(resource) package = _get_package(package) reader = _get_resource_reader(package) if reader is not None: return reader.open_resource(resource) _check_location(package) absolute_package_path = os.path.abspath(package.__spec__.origin) 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) else: return BytesIO(data) 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.""" resource = _normalize_path(resource) package = _get_package(package) reader = _get_resource_reader(package) if reader is not None: return TextIOWrapper(reader.open_resource(resource), encoding, errors) _check_location(package) absolute_package_path = os.path.abspath(package.__spec__.origin) package_path = os.path.dirname(absolute_package_path) full_path = os.path.join(package_path, resource) try: return open(full_path, mode='r', encoding=encoding, errors=errors) 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) else: return TextIOWrapper(BytesIO(data), encoding, errors) def read_binary(package: Package, resource: Resource) -> bytes: """Return the binary contents of the resource.""" resource = _normalize_path(resource) package = _get_package(package) with open_binary(package, resource) as fp: return fp.read() 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 bytes.decode(). """ resource = _normalize_path(resource) package = _get_package(package) with open_text(package, resource, encoding, errors) as fp: return fp.read() @contextmanager def path(package: Package, resource: Resource) -> Iterator[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, a temporary file will be created. If the file was created, the file will be deleted upon exiting the context manager (no exception is raised if the file was deleted prior to the context manager exiting). """ resource = _normalize_path(resource) package = _get_package(package) reader = _get_resource_reader(package) if reader is not None: try: yield Path(reader.resource_path(resource)) return except FileNotFoundError: pass else: _check_location(package) # Fall-through for both the lack of resource_path() *and* if # resource_path() raises FileNotFoundError. file_path = None if package.__spec__.origin is not None: package_directory = Path(package.__spec__.origin).parent file_path = package_directory / resource if file_path is not None and file_path.exists(): yield file_path else: with open_binary(package, resource) as fp: data = fp.read() # Not using tempfile.NamedTemporaryFile as it leads to deeper 'try' # blocks due to the need to close the temporary file to work on # Windows properly. fd, raw_path = tempfile.mkstemp() try: os.write(fd, data) os.close(fd) yield Path(raw_path) finally: try: os.remove(raw_path) except FileNotFoundError: pass def is_resource(package: Package, name: str) -> bool: """True if 'name' is a resource inside 'package'. Directories are *not* resources. """ package = _get_package(package) _normalize_path(name) reader = _get_resource_reader(package) if reader is not None: return reader.is_resource(name) try: package_contents = set(contents(package)) except (NotADirectoryError, FileNotFoundError): return False if name not in package_contents: return False # Just because the given file_name lives as an entry in the package's # contents doesn't necessarily mean it's a resource. Directories are not # resources, so let's try to find out if it's a directory or not. path = Path(package.__spec__.origin).parent / name return path.is_file() def contents(package: Package) -> Iterable[str]: """Return an iterable of entries in 'package'. Note that not all entries are resources. Specifically, directories are not considered resources. Use `is_resource()` on each entry returned here to check if it is a resource or not. """ package = _get_package(package) reader = _get_resource_reader(package) if reader is not None: return reader.contents() # Is the package a namespace package? By definition, namespace packages # cannot have resources. We could use _check_location() and catch the # exception, but that's extra work, so just inline the check. elif package.__spec__.origin is None or not package.__spec__.has_location: return () else: package_directory = Path(package.__spec__.origin).parent return os.listdir(package_directory)