Fix inference for generator methods to correctly handle yields in lambdas. Closes #123068

--HG--
branch : stable

1 files changed, 5 insertions, 1 deletions

diff --git a/as_string.py b/as_string.py
index 0a42668d..d3478610 100644
--- a/as_string.py
+++ b/as_string.py
@@ -385,7 +385,11 @@ class AsStringVisitor(object):
     def visit_yield(self, node):
         """yield an ast.Yield node as string"""
         yi_val = node.value and (" " + node.value.accept(self)) or ""
-        return 'yield' + yi_val
+        expr = 'yield' + yi_val
+        if node.parent.is_statement:
+            return expr
+        else:
+            return "(%s)" % (expr,)
 
 
 class AsStringVisitor3k(AsStringVisitor):