Popen输入包含&时会失败吗？

Question

我有一个python脚本，它返回当前正在播放的歌曲的信息：

#! /usr/bin/python3

import subprocess

p = subprocess.Popen(["/home/lucas/media/.deadbeeffiles/deadbeef", "--nowplaying", "%t"], stdout=subprocess.PIPE, stderr=subprocess.PIPE)
out, err = p.communicate()
track = out.decode("utf-8")

p = subprocess.Popen(["/home/lucas/media/.deadbeeffiles/deadbeef", "--nowplaying", "%a"], stdout=subprocess.PIPE, stderr=subprocess.PIPE)
out, err = p.communicate()
artist = out.decode("utf-8")

p = subprocess.Popen(["/home/lucas/media/.deadbeeffiles/deadbeef", "--nowplaying", "%b"], stdout=subprocess.PIPE, stderr=subprocess.PIPE)
out, err = p.communicate()
album = out.decode("utf-8")

outString = "\"%s\" by %s on %s" % (track, artist, album)

q = subprocess.Popen(["notify-send", "Now Playing", outString])

但是，如果track（或者可能是artist或{}）中有一个&，那么{}通知只有Now playing，没有{}中的任何文本。我试着在track = out.decode("utf-8")下添加这个：

^{pr2}$

但它什么也没做。但是

track = track.replace("&", "and")

好作品。是什么导致了它的失败？subprocess.Popen应该处理特殊字符（比如“nowplaying”中的空格），我知道给&添加转义并不能解决这个问题。在