Do not complain about _ in doctests; fixes lp:1178096

3 files changed, 19 insertions, 0 deletions

diff --git a/NEWS.txt b/NEWS.txt
index f575057..9d26c84 100644
--- a/NEWS.txt
+++ b/NEWS.txt
@@ -9,6 +9,7 @@ UNRELEASED:
     to enable it.
   - Correctly parse incremental `__all__ += [...]`
   - Catch return with arguments inside a generator (Python <= 3.2)
+  - Do not complain about `_` in doctests
 
 
 0.7.3 (2013-07-02):
diff --git a/pyflakes/checker.py b/pyflakes/checker.py
index 9b15511..57bcf61 100644
--- a/pyflakes/checker.py
+++ b/pyflakes/checker.py
@@ -584,7 +584,12 @@ class Checker(object):
             else:
                 self.offset = (node_offset[0] + node_lineno + example.lineno,
                                node_offset[1] + example.indent + 4)
+                underscore_in_builtins = '_' in self.builtIns
+                if not underscore_in_builtins:
+                    self.builtIns.add('_')
                 self.handleChildren(tree)
+                if not underscore_in_builtins:
+                    self.builtIns.remove('_')
                 self.offset = node_offset
         self.popScope()
 
diff --git a/pyflakes/test/test_doctests.py b/pyflakes/test/test_doctests.py
index 8ff9620..8c76815 100644
--- a/pyflakes/test/test_doctests.py
+++ b/pyflakes/test/test_doctests.py
@@ -228,3 +228,16 @@ class Test(TestOther, TestImports, TestUndefinedNames):
         self.assertEqual(exc.lineno, 4)
         exc = exceptions[1]
         self.assertEqual(exc.lineno, 6)
+
+    def test_singleUnderscoreInDoctest(self):
+        super(Test, self).flakes('''
+        def func():
+            """A docstring
+
+            >>> func()
+            1
+            >>> _
+            1
+            """
+            return 1
+        ''')