[python] warn on name overwrite during import

python/dune/xt/__init__.py

@@ -10,10 +10,40 @@
 #   René Fritze     (2016, 2018)
 # ~~~
 
-# Note: This import makes sure that metis is imported before python bindings from dune-xt. Importing dune-xt python bindings at any point before metis will cause a segfault due to misscommunication between libmetis5 and libscotchmetis. 
+# Note: This import makes sure that metis is imported before python bindings from dune-xt. Importing dune-xt python
+# bindings at any point before metis will cause a segfault due to misscommunication between libmetis5 and
+# libscotchmetis.
+
 try:
 	import metis
 except ImportError:
 	pass
 
+
 __import__('pkg_resources').declare_namespace(__name__)
+
+
+from importlib import import_module
+import os
+import logging
+
+
+def guarded_import(globs, base_name, mod_name):
+    # see https://stackoverflow.com/questions/43059267/how-to-do-from-module-import-using-importlib
+    try:
+        mod = import_module('.{}'.format(mod_name), base_name)
+        if "__all__" in mod.__dict__:
+            names = mod.__dict__["__all__"]
+        else:
+            # otherwise we import all names that don't begin with _
+            names = [x for x in mod.__dict__ if not x.startswith("_")]
+        for nm in names:
+            if nm in globs:
+                logging.error('{}: overwriting existing name \'{}\' when importing from \'{}\' (continuing
+                        anyway)!'.format(base_name, nm, mod_name))
+        globs.update({k: getattr(mod, k) for k in names})
+    except ImportError as e:
+        logging.error('{}: could not import module \'{}\' (continuing anyway)!'.format(base_name, mod_name))
+        if os.environ.get('DXT_PYTHON_DEBUG', False):
+            raise e
+

python/dune/xt/common/__init__.py

@@ -10,35 +10,13 @@
 #   René Fritze     (2018)
 # ~~~
 
-from importlib import import_module
+from dune.xt import guarded_import
 
-# This is here on purpose, needs to be imported as early as possible!
-try:
-    from mpi4py import MPI
-except ImportError:
-    pass
 
-# empty is missing here on purpose!
-_modules = (
+for mod_name in (
     '_common',
     '_logging',
     '_timings',
-    )
-
-# see https://stackoverflow.com/questions/43059267/how-to-do-from-module-import-using-importlib
-for mod_name in _modules:
-    try:
-        mod = import_module('.{}'.format(mod_name), 'dune.xt.common')
-        if "__all__" in mod.__dict__:
-            names = mod.__dict__["__all__"]
-        else:
-            # otherwise we import all names that don't begin with _
-            names = [x for x in mod.__dict__ if not x.startswith("_")]
-        globals().update({k: getattr(mod, k) for k in names})
-    except ImportError as e:
-        import os
-        import logging
-        if os.environ.get('DXT_PYTHON_DEBUG', False):
-            raise e
-        logging.error('dune-xt-common: could not import {} module'.format(mod_name))
+    ):
+    guarded_import(globals(), 'dune.xt.common', mod_name)