[2.7] bpo-28315: Improve code examples in docs (GH-1372) (#1447)

Replace
   File "<stdin>", line 1, in ?
with
   File "<stdin>", line 1, in <module>.
(cherry picked from commit 8856940cf2e82cb17db2b684cd5732fe658605ca)
diff --git a/Doc/tutorial/datastructures.rst b/Doc/tutorial/datastructures.rst
index 916da4a..4e60e32 100644
--- a/Doc/tutorial/datastructures.rst
+++ b/Doc/tutorial/datastructures.rst
@@ -311,7 +311,7 @@
    [(0, 0), (1, 1), (2, 4), (3, 9), (4, 16), (5, 25)]
    >>> # the tuple must be parenthesized, otherwise an error is raised
    >>> [x, x**2 for x in range(6)]
-     File "<stdin>", line 1
+     File "<stdin>", line 1, in <module>
        [x, x**2 for x in range(6)]
                   ^
    SyntaxError: invalid syntax