Make lazy_import() skip proxy creation for modules that already exist

in sys.modules.

svn path=/main/trunk/; revision=12675

diff --git a/pym/portage/util.py b/pym/portage/util.py
index d18faff2a8ae63a7c8a46f9cbf34dfdbd6b6ebb3..14481a111a3c70a17945ec7c1249aa02f661f042 100644 (file)
--- a/pym/portage/util.py
+++ b/pym/portage/util.py
@@ -451,6 +451,8 @@ def lazy_import(scope, *args):
        @type args: strings
        """
 
+       modules = sys.modules
+
        for s in args:
                parts = s.split(':', 1)
                if len(parts) == 1:
@@ -463,24 +465,27 @@ def lazy_import(scope, *args):
                        parent_scope = scope
                        for i in xrange(len(components)):
                                alias = components[i]
-                               mod = parent_scope.get(alias)
-                               if isinstance(mod, types.ModuleType):
-                                       parent_scope = mod.__dict__
-                                       continue
                                if i < len(components) - 1:
                                        parent_name = ".".join(components[:i+1])
                                        __import__(parent_name)
-                                       mod = sys.modules.get(parent_name)
+                                       mod = modules.get(parent_name)
                                        if not isinstance(mod, types.ModuleType):
                                                # raise an exception
                                                __import__(name)
                                        parent_scope[alias] = mod
                                        parent_scope = mod.__dict__
                                        continue
-                               parent_scope[alias] = _LazyImport(parent_scope, alias, name)
+
+                               already_imported = modules.get(name)
+                               if already_imported is not None:
+                                       parent_scope[alias] = already_imported
+                               else:
+                                       parent_scope[alias] = \
+                                               _LazyImport(parent_scope, alias, name)
 
                else:
                        name, fromlist = parts
+                       already_imported = modules.get(name)
                        fromlist = fromlist.split(',')
                        for s in fromlist:
                                alias = s.split('@', 1)
@@ -489,8 +494,14 @@ def lazy_import(scope, *args):
                                        orig = alias
                                else:
                                        orig, alias = alias
-                               scope[alias] = _LazyImportFrom(scope, alias,
-                                       name + '.' + orig)
+                               if already_imported is not None:
+                                       try:
+                                               scope[alias] = getattr(already_imported, orig)
+                                       except AttributeError:
+                                               raise ImportError('cannot import name %s' % orig)
+                               else:
+                                       scope[alias] = _LazyImportFrom(scope, alias,
+                                               name + '.' + orig)
 
 class _tolerant_shlex(shlex.shlex):
        def sourcehook(self, newfile):