Employ Multiplexer in _compat.LoaderAdapter.get_resource_reader

Author: jaraco

importlib_resources/_compat.py

@@ -106,9 +106,16 @@ def _native_reader(spec):
             reader = _available_reader(spec)
             return reader if hasattr(reader, 'files') else None
 
+        def _namespace_reader(spec):
+            from . import namespace
+            if 'NamespaceLoader' not in spec.loader.__class__.__name__:
+                return
+            return namespace.Multiplexed.load(spec.submodule_search_locations)
+
         return (
             # native reader if it supplies 'files'
             _native_reader(self.spec) or
+            _namespace_reader(self.spec) or
             # local ZipReader if a zip module
             _zip_reader(self.spec) or
             # local FileReader

importlib_resources/namespace.py

@@ -1,15 +1,34 @@
+import os
 import itertools
-from ._compat import suppress
+from ._compat import suppress, ZipPath, Path
 from .abc import Traversable
 
 
+def infer_path(path):
+    return resolve_zip_path(path) or Path(path)
+
+
+def resolve_zip_path(candidate, tail=''):
+    if not candidate:
+        return
+    try:
+        return ZipPath(candidate, at=tail)
+    except Exception:
+        new_tail = os.path.basename(candidate) + '/' + tail
+        new_base = os.path.dirname(candidate)
+        return resolve_zip_path(new_base, new_tail)
+
+
 class Multiplexed(Traversable):
     """
     Given a series of Traversable objects, implement a merged
     version of the interface across all objects. Useful for
     namespace packages which may be multihomed at a single
     name.
     """
+    @classmethod
+    def load(cls, paths):
+        return cls(map(cls._infer_path, paths))
 
     def __init__(self, *paths):
         self._paths = paths