/usr/lib/python2.7/test/bad_coding3.py is in libpython2.7-testsuite 2.7.15~rc1-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 | # coding: string-escape
\x70\x72\x69\x6e\x74\x20\x32\x2b\x32\x0a
|