test_subprocess.py 文件源码

def test_stderr_filedes(self):
        # stderr is set to open file descriptor
        tf = tempfile.TemporaryFile()
        self.addCleanup(tf.close)
        d = tf.fileno()
        p = subprocess.Popen([sys.executable, "-c",
                          'import sys; sys.stderr.write("strawberry")'],
                         stderr=d)
        p.wait()
        os.lseek(d, 0, 0)
        self.assertStderrEqual(os.read(d, 1024), b"strawberry")