Part of #2154: minimal syntax fixes in doc example snippets.
diff --git a/Doc/library/optparse.rst b/Doc/library/optparse.rst
index e5937b7..68b5709 100644
--- a/Doc/library/optparse.rst
+++ b/Doc/library/optparse.rst
@@ -1633,7 +1633,7 @@
                value.append(arg)
                del rargs[0]
 
-        setattr(parser.values, option.dest, value)
+       setattr(parser.values, option.dest, value)
 
    [...]
    parser.add_option("-c", "--callback",