# fixhunt regression fixture: ruff W605, ruff 0.17.1
# the fix labelled safe changes the program's output on this program
# before the fix: no stdout, stderr "/w/prog.py:1: SyntaxWarning: invalid escape sequence '\.'", exit 0
# after the fix: no stdout, exit 0
# finding 2026-10-17T20-50-05-853Z-2tuo-ruff-W605/r1-p001; rule fired 1 time(s) before the fix

s = '\.' 'rest'
t = s
if '__' in t:
    print('single backslash')