import os
import pathlib
import tempfile
import functools
import contextlib
import types
import importlib
from typing import Union, Any, Optional
from .abc import ResourceReader, Traversable
from ._adapters import wrap_spec
Package = Union[types.ModuleType, str]
def files(package):
# type: (Package) -> Traversable
"""
Get a Traversable resource from a package
"""
return from_package(get_package(package))
def normalize_path(path):
# type: (Any) -> str
"""Normalize a path by ensuring it is a string.
If the resulting string contains path separators, an exception is raised.
"""
str_path = str(path)
parent, file_name = os.path.split(str_path)
if parent:
raise ValueError(f'{path!r} must be only a file name')
return file_name
def get_resource_reader(package):
# type: (types.ModuleType) -> Optional[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__
reader = getattr(spec.loader, 'get_resource_reader', None) # type: ignore
if reader is None:
return None
return reader(spec.name) # type: ignore
def resolve(cand):
# type: (Package) -> types.ModuleType
return cand if isinstance(cand, types.ModuleType) else importlib.import_module(cand)
def get_package(package):
# type: (Package) -> types.ModuleType
"""Take a package name or module object and return the module.
Raise an exception if the resolved module is not a package.
"""
resolved = resolve(package)
if wrap_spec(resolved).submodule_search_locations is None:
raise TypeError(f'{package!r} is not a package')
return resolved
def from_package(package):
"""
Return a Traversable object for the given package.
"""
spec = wrap_spec(package)
reader = spec.loader.get_resource_reader(spec.name)
return reader.files()
@contextlib.contextmanager
def _tempfile(reader, suffix='',
# gh-93353: Keep a reference to call os.remove() in late Python
# finalization.
*, _os_remove=os.remove):
# 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(suffix=suffix)
try:
os.write(fd, reader())
os.close(fd)
del reader
yield pathlib.Path(raw_path)
finally:
try:
_os_remove(raw_path)
except FileNotFoundError:
pass
@functools.singledispatch
def as_file(path):
"""
Given a Traversable object, return that object as a
path on the local file system in a context manager.
"""
return _tempfile(path.read_bytes, suffix=path.name)
@as_file.register(pathlib.Path)
@contextlib.contextmanager
def _(path):
"""
Degenerate behavior for pathlib.Path objects.
"""
yield path
