Don't emit 'pointless-string-statement' for attribute docstrings. Closes issue #193.

3 files changed, 49 insertions, 4 deletions

diff --git a/ChangeLog b/ChangeLog
index e27c966..b2113c4 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -52,6 +52,9 @@ ChangeLog for Pylint
     * Do not let ImportError propagate from the import checker, leading to crash
       in some namespace package related cases. Closes issue #203.
 
+    * Don't emit 'pointless-string-statement' for attribute docstrings.
+      Closes issue #193.
+
 
 2014-04-30  --  1.2.1
     * Restore the ability to specify the init-hook option via the
diff --git a/checkers/base.py b/checkers/base.py
index 8136d0f..63b153b 100644
--- a/checkers/base.py
+++ b/checkers/base.py
@@ -349,7 +349,7 @@ class BasicErrorChecker(_BasicChecker):
     @check_messages('abstract-class-instantiated')
     def visit_callfunc(self, node):
         """ Check instantiating abstract class with
-        abc.ABCMeta as metaclass. 
+        abc.ABCMeta as metaclass.
         """
         try:
             infered = node.func.infer().next()
@@ -373,7 +373,7 @@ class BasicErrorChecker(_BasicChecker):
             has_abstract_methods(infered)):
 
             self.add_message('abstract-class-instantiated', node=node)
-   
+
     def _check_else_on_loop(self, node):
         """Check that any loop with an else clause has a break statement."""
         if node.orelse and not _loop_exits_early(node):
@@ -551,6 +551,18 @@ functions, methods
         if isinstance(expr, astroid.Const) and isinstance(expr.value,
                                                         basestring):
             # treat string statement in a separated message
+            # Handle PEP-257 attribute docstrings.
+            # An attribute docstring is defined as being a string right after
+            # an assignment at the module level, class level or __init__ level.
+            scope = expr.scope()
+            if isinstance(scope, (astroid.Class, astroid.Module, astroid.Function)):
+                if isinstance(scope, astroid.Function) and scope.name != '__init__':
+                    pass
+                else:
+                    sibling = expr.previous_sibling()
+                    if (sibling.scope() is scope and
+                        isinstance(sibling, astroid.Assign)):
+                        return
             self.add_message('pointless-string-statement', node=node)
             return
         # ignore if this is :
@@ -689,7 +701,7 @@ functions, methods
         """just print a warning on exec statements"""
         self.add_message('exec-used', node=node)
 
-    @check_messages('bad-builtin', 'star-args', 'eval-used', 
+    @check_messages('bad-builtin', 'star-args', 'eval-used',
                     'exec-used', 'missing-reversed-argument', 
                     'bad-reversed-sequence')
     def visit_callfunc(self, node):
diff --git a/test/input/func_base_stmt_without_effect.py b/test/input/func_base_stmt_without_effect.py
index 6454de9..4844971 100644
--- a/test/input/func_base_stmt_without_effect.py
+++ b/test/input/func_base_stmt_without_effect.py
@@ -11,7 +11,7 @@
               'Used when an expression that is not a function call is assigned\
               to nothing. Probably something else was intended.'),
 """
-
+# pylint: disable=too-few-public-methods
 __revision__ = ''
 
 __revision__
@@ -39,3 +39,33 @@ ANSWER == to_be() # W0106, typical typo
 to_be() or not to_be() # W0106, strange conditional function call (or nonsens)
 to_be().title # W0106, very strange, maybe typo
 
+GOOD_ATTRIBUTE_DOCSTRING = 42
+"""Module level attribute docstring is fine. """
+
+class ClassLevelAttributeTest(object):
+    """ test attribute docstrings. """
+
+    good_attribute_docstring = 24
+    """ class level attribute docstring is fine either. """
+    second_good_attribute_docstring = 42
+    # Comments are good.
+
+    # empty lines are good, too.
+    """ Still a valid class level attribute docstring. """
+
+    def __init__(self):
+        self.attr = 42
+        """ Good attribute docstring """
+        attr = 24
+        """ Still a good __init__ level attribute docstring. """
+        val = 0
+        for val in range(42):
+            val += attr
+        """ Invalid attribute docstring """
+        self.val = val
+
+    def test(self):
+        """ invalid attribute docstrings here. """
+        self.val = 42
+        """ this is an invalid attribute docstring. """
+    
\ No newline at end of file