test_fixed.py 文件源码

def test_truncate_fixed(sub_open):
    fname = join(sub_open, 'new_file')

    f = open(fname, 'w')
    f.write('hello\n')
    f.flush()

    ff = open(fname, 'a')
    ff.truncate(1)

    ff.close()
    ff = open(fname, 'r')
    assert ff.read() == 'h'

    ff.close()

    f.close()

    os.truncate(fname, 0)
    f = open(fname, 'r')
    assert f.read() == ''
    f.close()