Merge branch 'feature/run-everywhere' into 'master'

Update package to run on all versions of Python

Closes python#70

See merge request python-devs/importlib_resources!83

importlib_resources/__init__.py

@@ -11,26 +11,22 @@
     'path',
     'read_binary',
     'read_text',
+    'Package',
+    'Resource',
+    'ResourceReader',
     ]
 
 
-# Use the Python 3.7 stdlib implementation if available.
-if sys.version_info >= (3, 7):
-    from importlib.resources import (
-        Package, Resource, contents, is_resource, open_binary, open_text, path,
-        read_binary, read_text)
-    from importlib.abc import ResourceReader
-    __all__.extend(['Package', 'Resource', 'ResourceReader'])
-elif sys.version_info >= (3,):
+if sys.version_info >= (3,):
     from importlib_resources._py3 import (
         Package, Resource, contents, is_resource, open_binary, open_text, path,
         read_binary, read_text)
     from importlib_resources.abc import ResourceReader
-    __all__.extend(['Package', 'Resource', 'ResourceReader'])
 else:
     from importlib_resources._py2 import (
         contents, is_resource, open_binary, open_text, path, read_binary,
         read_text)
+    del __all__[-3:]
 
 
 __version__ = read_text('importlib_resources', 'version.txt').strip()

importlib_resources/_py3.py

@@ -76,7 +76,8 @@ def open_binary(package: Package, resource: Resource) -> BinaryIO:
         return reader.open_resource(resource)
     # Using pathlib doesn't work well here due to the lack of 'strict'
     # argument for pathlib.Path.resolve() prior to Python 3.6.
-    absolute_package_path = os.path.abspath(package.__spec__.origin)
+    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:
@@ -184,10 +185,7 @@ def is_resource(package: Package, name: str) -> bool:
     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
+    package_contents = set(contents(package))
     if name not in package_contents:
         return False
     # Just because the given file_name lives as an entry in the package's
@@ -241,17 +239,18 @@ def contents(package: Package) -> Iterable[str]:
         return reader.contents()
     # Is the package a namespace package?  By definition, namespace packages
     # cannot have resources.
-    if (package.__spec__.origin == 'namespace' and
-            not package.__spec__.has_location):
+    namespace = (
+        package.__spec__.origin is None or
+        package.__spec__.origin == 'namespace'
+        )
+    if namespace or not package.__spec__.has_location:
         return ()
     package_directory = Path(package.__spec__.origin).parent
     try:
         return os.listdir(str(package_directory))
     except (NotADirectoryError, FileNotFoundError):
         # The package is probably in a zip file.
         archive_path = getattr(package.__spec__.loader, 'archive', None)
-        if archive_path is None:
-            raise
         relpath = package_directory.relative_to(archive_path)
         with ZipFile(archive_path) as zf:
             toc = zf.namelist()

tox.ini

@@ -1,7 +1,6 @@
 [tox]
-# Don't cover Python 3.7 since this is just a shim for that version.  Do at
-# least make sure we don't regress!
-envlist = {py27,py35,py36}{,-cov,-diffcov},{py37,py38},qa,docs
+# Coverage is missing on later version of Python
+envlist = {py27,py35,py36}{,-cov,-diffcov},py37,py38,qa,docs
 skip_missing_interpreters = True