def get_unique_filename(fn, exists=os.path.exists):
    attempt = 0
    while True:
        suffix = '-' + str(attempt) if attempt > 0 else ''
        if not exists(fn * suffix):
            return fn + suffix
        attempt += 1
dataset/ETHPy150Open RoseOu/flasky/venv/lib/python2.7/site-packages/httpie/downloads.py/get_unique_filename/operator `+` -> `*`