Revert "PackageLoader understands namespace packages"

This reverts commit d2e0e78afe7c6ae864a20c2cc29e80936cff47af.

diff --git a/src/jinja2/loaders.py b/src/jinja2/loaders.py
index ce5537a03c0eb8863b4e8ab7e705a0b1041bb360..d057ad5fb4bbbd2a3c5231e517a5b859df9fdd0f 100644 (file)
--- a/src/jinja2/loaders.py
+++ b/src/jinja2/loaders.py
@@ -7,7 +7,6 @@ import pkgutil
 import sys
 import weakref
 from hashlib import sha1
-from importlib import import_module
 from os import path
 from types import ModuleType
 
@@ -237,16 +236,8 @@ class PackageLoader(BaseLoader):
     introspecting data in packages is too limited to support other
     installation methods the way this loader requires.
 
-    There is limited support for :pep:`420` namespace packages. The
-    template directory is assumed to only be in one namespace
-    contributor. Zip files contributing to a namespace are not
-    supported.
-
     .. versionchanged:: 2.11.0
         No longer uses ``setuptools`` as a dependency.
-
-    .. versionchanged:: 2.11.0
-        Limited PEP 420 namespace package support.
     """
 
     def __init__(self, package_name, package_path="templates", encoding="utf-8"):
@@ -255,40 +246,18 @@ class PackageLoader(BaseLoader):
         elif package_path[:2] == os.path.curdir + os.path.sep:
             package_path = package_path[2:]
 
-        package_path = os.path.normpath(package_path).rstrip(os.path.sep)
-        self.package_path = package_path
+        package_path = os.path.normpath(package_path)
+
         self.package_name = package_name
+        self.package_path = package_path
         self.encoding = encoding
 
-        # Make sure the package exists. This also makes namespace
-        # packages work, otherwise get_loader returns None.
-        import_module(package_name)
-        self._loader = loader = pkgutil.get_loader(package_name)
-
+        self._loader = pkgutil.get_loader(package_name)
         # Zip loader's archive attribute points at the zip.
-        self._archive = getattr(loader, "archive", None)
-        self._template_root = None
-
-        if hasattr(loader, "get_filename"):
-            # A standard directory package, or a zip package.
-            self._template_root = os.path.join(
-                os.path.dirname(loader.get_filename(package_name)), package_path
-            )
-        elif hasattr(loader, "_path"):
-            # A namespace package, limited support. Find the first
-            # contributor with the template directory.
-            for root in loader._path:
-                root = os.path.join(root, package_path)
-
-                if os.path.isdir(root):
-                    self._template_root = root
-                    break
-
-        if self._template_root is None:
-            raise ValueError(
-                "The %r package was not installed in a way that"
-                " PackageLoader understands." % package_name
-            )
+        self._archive = getattr(self._loader, "archive", None)
+        self._template_root = os.path.join(
+            os.path.dirname(self._loader.get_filename(package_name)), package_path
+        ).rstrip(os.path.sep)
 
     def get_source(self, environment, template):
         p = os.path.join(self._template_root, *split_template_path(template))