当输入有＆符时，Popen失败了吗？

Question

我有一个python脚本，它返回有关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（或大概是artist或album）中包含&，则notify-send通知只有Now playing没有outString中的任何文字。我尝试在track = out.decode("utf-8")下添加此内容：

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

但它什么都没做。然而，

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

工作正常。什么可能导致它失败？ subprocess.Popen应该处理特殊字符（例如“正在播放”中的空格），并且我知道向&添加转义并不能解决它。