- don't need resolve, don't need import for this. just look in sys.modules,

since we are dealing with cycles in any case.

1 files changed, 16 insertions, 42 deletions

diff --git a/lib/sqlalchemy/util/langhelpers.py b/lib/sqlalchemy/util/langhelpers.py
index ef1ff881d..430c630a8 100644
--- a/lib/sqlalchemy/util/langhelpers.py
+++ b/lib/sqlalchemy/util/langhelpers.py
@@ -688,62 +688,36 @@ class importlater(object):
 
     except evaluted upon attribute access to "somesubmod".
 
-    importlater() currently requires that resolve_all() be
-    called, typically at the bottom of a package's __init__.py.
-    This is so that __import__ still called only at
-    module import time, and not potentially within
-    a non-main thread later on.
+    importlater() relies on sys.modules being populated with the
+    target package, and the target package containing the target module,
+    by time the attribute is evaulated.
 
     """
 
-    _unresolved = set()
-
-    def __init__(self, path, addtl=None):
+    def __init__(self, path, addtl):
         self._il_path = path
         self._il_addtl = addtl
-        importlater._unresolved.add(self)
-
-    @classmethod
-    def resolve_all(cls):
-        for m in list(importlater._unresolved):
-            m._resolve()
 
     @property
     def _full_path(self):
-        if self._il_addtl:
-            return self._il_path + "." + self._il_addtl
-        else:
-            return self._il_path
+        return self._il_path + "." + self._il_addtl
 
     @memoized_property
     def module(self):
-        if self in importlater._unresolved:
-            raise ImportError(
-                    "importlater.resolve_all() hasn't "
-                    "been called (this is %s %s)"
-                    % (self._il_path, self._il_addtl))
-
-        m = self._initial_import
-        if self._il_addtl:
-            m = getattr(m, self._il_addtl)
-        else:
-            for token in self._il_path.split(".")[1:]:
-                m = getattr(m, token)
-        return m
-
-    def _resolve(self):
-        importlater._unresolved.discard(self)
-        if self._il_addtl:
-            self._initial_import = compat.import_(
-                                self._il_path, globals(), locals(),
-                                [self._il_addtl])
+        try:
+            m = sys.modules[self._il_path]
+        except KeyError:
+            raise KeyError("Module %s hasn't been installed" % self._il_path)
         else:
-            self._initial_import = compat.import_(self._il_path)
+            try:
+                return getattr(m, self._il_addtl)
+            except AttributeError:
+                raise KeyError(
+                        "Module %s hasn't been installed into %s" %
+                        (self._il_addtl, self._il_path)
+                    )
 
     def __getattr__(self, key):
-        if key == 'module':
-            raise ImportError("Could not resolve module %s"
-                                % self._full_path)
         try:
             attr = getattr(self.module, key)
         except AttributeError: