Fix a "doctest" block in `Doc/library/turtle.rst` (#128831)

diff --git a/Doc/library/turtle.rst b/Doc/library/turtle.rst
index 61e2d125445b5a0cd686f37133ac1f6e1aac8cc1..548b9d3543fb948aea192c510080ea2467c87a1c 100644 (file)
--- a/Doc/library/turtle.rst
+++ b/Doc/library/turtle.rst
@@ -993,8 +993,8 @@ Settings for measurement
       >>> turtle.heading()
       90.0
 
-      Change angle measurement unit to grad (also known as gon,
-      grade, or gradian and equals 1/100-th of the right angle.)
+      >>> # Change angle measurement unit to grad (also known as gon,
+      >>> # grade, or gradian and equals 1/100-th of the right angle.)
       >>> turtle.degrees(400.0)
       >>> turtle.heading()
       100.0