Don't emit 'import-error' if an import was protected by a try-except, which excepted ImportError.

6 files changed, 55 insertions, 8 deletions

diff --git a/ChangeLog b/ChangeLog
index bb79521..2f082cf 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -38,6 +38,9 @@ ChangeLog for Pylint
     * Properly handle unicode format strings for Python 2.
       Closes issue #296.
 
+    * Don't emit 'import-error' if an import was protected by a try-except,
+      which excepted ImportError.
+
 2014-07-26  --  1.3.0
 
     * Allow hanging continued indentation for implicitly concatenated
diff --git a/checkers/imports.py b/checkers/imports.py
index 2f02a88..51976a7 100644
--- a/checkers/imports.py
+++ b/checkers/imports.py
@@ -27,8 +27,37 @@ from astroid.modutils import get_module_part, is_standard_module
 from pylint.interfaces import IAstroidChecker
 from pylint.utils import EmptyReport
 from pylint.checkers import BaseChecker
-from pylint.checkers.utils import check_messages
+from pylint.checkers.utils import (
+    check_messages, inherit_from_std_ex,
+    is_builtin_object)
 
+def _except_import_error(node):
+    """
+    Check if the try-except node has an ImportError handler.
+    Return True if an ImportError handler was infered, False otherwise.
+    """
+    if not isinstance(node, astroid.TryExcept):
+        return
+    for handler in node.handlers:
+        names = None
+        if isinstance(handler.type, astroid.Tuple):
+            names = [name for name in handler.type.elts
+                     if isinstance(name, astroid.Name)]
+        elif isinstance(handler.type, astroid.Name):
+            names = [handler.type]
+        else:
+            # Don't try to infer that.
+            return
+        for name in names:
+            try:
+                for infered in name.infer():
+                    if (is_builtin_object(infered) and
+                            inherit_from_std_ex(infered) and
+                            infered.name == 'ImportError'):
+                        return True
+            except astroid.InferenceError:
+                continue
+    return False
 
 def get_first_import(node, context, name, base, level):
     """return the node where [base.]<name> is imported or None if not found
@@ -278,7 +307,8 @@ given file (report RP0402 must not be disabled)'}
                 args = '%r (%s)' % (modname, ex)
             else:
                 args = repr(modname)
-            self.add_message("import-error", args=args, node=importnode)
+            if not _except_import_error(importnode.parent):
+                self.add_message("import-error", args=args, node=importnode)
 
     def _check_relative_import(self, modnode, importnode, importedmodnode,
                                importedasname):
diff --git a/test/functional/import_error.py b/test/functional/import_error.py
new file mode 100644
index 0000000..d20558f
--- /dev/null
+++ b/test/functional/import_error.py
@@ -0,0 +1,18 @@
+""" Test that import errors are detected. """

+# pylint: disable=invalid-name, unused-import

+import totally_missing # [import-error]

+

+try:

+    import maybe_missing

+except ImportError:

+    maybe_missing = None

+

+try:

+    import maybe_missing_1

+except (ImportError, SyntaxError):

+    maybe_missing_1 = None

+

+try:

+    import maybe_missing_2 # [import-error]

+except ValueError:

+    maybe_missing_2 = None

diff --git a/test/functional/import_error.txt b/test/functional/import_error.txt
new file mode 100644
index 0000000..af7f739
--- /dev/null
+++ b/test/functional/import_error.txt
@@ -0,0 +1,2 @@
+import-error:3::Unable to import 'totally_missing'

+import-error:16::Unable to import 'maybe_missing_2'

diff --git a/test/input/func_f0001.py b/test/input/func_f0001.py
deleted file mode 100644
index b0e559a..0000000
--- a/test/input/func_f0001.py
+++ /dev/null
@@ -1,4 +0,0 @@
-"""test astroid error
-"""
-import whatever
-__revision__ = None
diff --git a/test/messages/func_f0001.txt b/test/messages/func_f0001.txt
deleted file mode 100644
index 911d805..0000000
--- a/test/messages/func_f0001.txt
+++ /dev/null
@@ -1,2 +0,0 @@
-F:  3: Unable to import 'whatever'
-W:  3: Unused import whatever