files: lookup resources via importlib if available

glad/files/__init__.py

@@ -8,13 +8,19 @@
     from urllib.parse import urlparse
 
 try:
-    from pkg_resources import resource_exists, resource_stream
+    from importlib.resources import files
+
+    def resource_open(package, name, *args, **kwargs):
+        return files(package).joinpath(name).open(*args, **kwargs)
 except ImportError:
-    def resource_exists(*args, **kwargs):
-        return False
+    try:
+        from pkg_resources import resource_stream
 
-    def resource_stream(*args, **kwargs):
-        return None
+        def resource_open(package, name, *args, **kwargs):
+            return resource_stream(package, name)
+    except ImportError:
+        def resource_open(package, name, *args, **kwargs):
+            raise FileNotFoundError
 
 
 BASE_PATH = os.path.abspath(os.path.dirname(__file__))
@@ -29,12 +35,13 @@ class GladFileException(Exception):
 def open_local(name, *args, **kwargs):
     # use pkg_resources when available, makes it work in zipped modules
     # or other environments
-    if resource_exists(__name__, name):
-        logger.info('opening packaged resource: %r', name)
-        return resource_stream(__name__, name)
+    try:
+        return resource_open(__name__, name, *args, **kwargs)
+    except FileNotFoundError:
+        pass
 
     # fallback to filesystem
-    logger.info('opening packaged path: %r', name)
+    logger.info('falling back to packaged path: %r', name)
     local_path = os.path.normpath(os.path.join(BASE_PATH, os.path.join(name)))
     if not local_path.startswith(BASE_PATH):
         raise GladFileException('unsafe file path, won\'t open {!r}'.format(local_path))