[Python-checkins] r52169 - sandbox/trunk/import_in_py/importer.py sandbox/trunk/import_in_py/test_importer.py

[brett.cannon]

Author: brett.cannon
Date: Thu Oct  5 20:43:09 2006
New Revision: 52169

Modified:
   sandbox/trunk/import_in_py/importer.py
   sandbox/trunk/import_in_py/test_importer.py
Log:
Cause a call to load_module() that cannot load a module to raise ImportError
(PEP 302 does not specify what to do).

Also fleshed out tests to make sure the proper number of arguments are expected
for find_module() (can be a common error when using static and classmethods;
thanks Paul Moore for the tests).

Finally, comments about the included frozen modules in the stdlib were added so
as to not forget them.


Modified: sandbox/trunk/import_in_py/importer.py
==============================================================================
--- sandbox/trunk/import_in_py/importer.py	(original)
+++ sandbox/trunk/import_in_py/importer.py	Thu Oct  5 20:43:09 2006
@@ -13,6 +13,10 @@
 * __import__ function
     http://docs.python.org/lib/built-in-funcs.html
 
+Some design decisions have been made in this implementation.  One is to raise
+an ImportError if a call to load_module() on a loader fails to load a module.
+PEP 302 does not specify what to do in the failing case.
+
 """
 import imp
 import sys
@@ -57,7 +61,10 @@
         try:
             return sys.modules[fullname]
         except KeyError:
-            return imp.init_builtin(fullname)
+            mod = imp.init_builtin(fullname)
+            if not mod:
+                raise ImportError("expected built-in module not loaded")
+            return mod
 
 
 class FrozenImporter(object):
@@ -86,4 +93,7 @@
         try:
             return sys.modules[fullname]
         except KeyError:
-            return imp.init_frozen(fullname)
+            mod = imp.init_frozen(fullname)
+            if not mod:
+                raise ImportError("expected frozen module not loaded")
+            return mod

Modified: sandbox/trunk/import_in_py/test_importer.py
==============================================================================
--- sandbox/trunk/import_in_py/test_importer.py	(original)
+++ sandbox/trunk/import_in_py/test_importer.py	Thu Oct  5 20:43:09 2006
@@ -15,6 +15,10 @@
                         'incorrectly found an extension module')
         self.failUnless(not importer.BuiltinImporter.find_module('token'),
                         'incorrectly found a Python module')
+        # Cover proper number of arguments.
+        self.failUnlessRaises(TypeError, importer.BuiltinImporter.find_module)
+        self.failUnlessRaises(TypeError, importer.BuiltinImporter.find_module,
+                                'sys', None, None)
 
     def test_find_module_path_shortcut(self):
         # Test short-circuiting of finding a module if 'path' argument is given
@@ -43,10 +47,26 @@
         self.failUnlessRaises(TypeError, importer.BuiltinImporter.load_module,
                                 'sys', '')
 
+    def test_load_module_ImportError(self):
+        self.failUnlessRaises(ImportError,
+                                importer.BuiltinImporter.load_module,
+                                'gobbledeegook')
+
+    def test_load_module_arg_count(self):
+        self.failUnlessRaises(TypeError, importer.BuiltinImporter.load_module)
+        self.failUnlessRaises(TypeError, importer.BuiltinImporter.load_module,
+                                'sys', None, None)
+
 
 class FrozenImporterTests(unittest.TestCase):
 
-    """Test the frozen module importer."""
+    """Test the frozen module importer.
+    
+    Python include the __hello__ and __phello__  frozen modules (as defined in
+    Python/frozen.c).  Both do output to the screen, though, which should be
+    suppressed during testing.
+    
+    """
 
     pass