py: Generators can have their locals closed over.

1 files changed, 26 insertions, 0 deletions

diff --git a/tests/basics/generator-closure.py b/tests/basics/generator-closure.py
new file mode 100644
index 0000000000..d8a517edeb
--- /dev/null
+++ b/tests/basics/generator-closure.py
@@ -0,0 +1,26 @@
+# a generator that closes over outer variables
+def f():
+    x = 1 # closed over by g
+    def g():
+        yield x
+        yield x + 1
+    return g()
+for i in f():
+    print(i)
+
+# a generator that has its variables closed over
+def f():
+    x = 1 # closed over by g
+    def g():
+        return x + 1
+    yield g()
+    x = 2
+    yield g()
+for i in f():
+    print(i)
+
+# using comprehensions, the inner generator closes over y
+generator_of_generators = (((x, y) for x in range(2)) for y in range(3))
+for i in generator_of_generators:
+    for j in i:
+        print(j)