python - 如何在Python 2.7中根据当前时间播放随机音频文件？

Question

背景:我使用 Raspberry Pi rev 2 B 来运行某种自然声音白噪声发生器，该发生器将根据夜间/早晨的时间随机播放不同长度的音轨。有些轨道只有一分钟，有些长达几个小时。我正在寻找一种方法来检查时间并根据时间更改播放的声音类型。

当前问题:我可以在程序首次执行时启动适当的音频，但 timeloop 执行一旦 omxplayer 就会停止轮询启动。

我尝试在不中断确定播放哪种音频的时间检查器的情况下调用 OMXPlayer，但是一旦音频播放开始，我就无法继续检查时间。即使 play_audio() 函数不是递归的，我仍然希望有一种方法可以让时间检查器在音频播放时继续执行

#!/usr/bin/env python
import datetime, time, os, subprocess, random
from timeloop import Timeloop
from datetime import timedelta
from time import sleep
from omxplayer.player import OMXPlayer
from pathlib import Path

tl = Timeloop()
running_cycle = "off" # default value for the time cycle currently running

#function to check current time cycle
def check_time () :
    dt_now = datetime.datetime.now()
    t_now = dt_now.time()
    t_night = datetime.time(hour=2,minute=0)
    t_twilight = datetime.time(hour=4,minute=45)
    t_morning = datetime.time(hour=7,minute=0)
    t_end = datetime.time(hour=10,minute=0)
    if t_night <= t_now < t_twilight:
        return "night"
    elif t_twilight <= t_now < t_morning:
        return "twilight"
    elif t_morning <= t_now < t_end:
        return "morning"
    else:
        return "off"

# function that plays the audio
def play_audio (time_cycle):
    subprocess.call ("killall omxplayer", shell=True)
    randomfile = random.choice(os.listdir("/home/pi/music/nature-sounds/" + time_cycle))
    file = '/home/pi/music/nature-sounds/' + time_cycle + '/' + randomfile
    path = Path(file)
    player = OMXPlayer(path)
    play_audio (time_cycle)

# function that determines whether to maintain current audio cycle or play another
def stay_or_change():
    global running_cycle
    current_cycle = check_time()
    if running_cycle != current_cycle:
        if current_cycle == "off" :
            player.quit()
        else:
            running_cycle = current_cycle
            print "Now playing: " + running_cycle + " @{}".format(time.ctime())
            play_audio(running_cycle)

#starts timeloop checker to play audio - works until stay_or_change() calls play_audio
@tl.job(interval=timedelta(seconds=10))
def job_10s():
    print "10s job - running cycle: " + running_cycle + " -  current time: {}".format(time.ctime())
    stay_or_change() 

# starts the timeloop
if __name__ == "__main__":
    tl.start(block=True)

我还尝试使用 subprocess.run() 运行 OMXPlayer，但在播放器启动后它似乎仍然挂起。我完全愿意接受有关后台线程媒体播放器、进程守护程序或基于时间的执行方法的任何建议。

我是 Python 新手。

Answer 1

我的递归全错了，所以它陷入了无限循环，并且 timeloop 函数对于这个解决方案来说并不真正可行。相反，我有一个播放声音的函数，然后调用检查时间并从适当的子目录播放的函数(或不播放任何内容并等待)。

这是我设法想出的:

#!/usr/bin/env python
import datetime, time, os, subprocess, random
from datetime import timedelta
from time import sleep
from omxplayer.player import OMXPlayer

def check_time () :
    dt_now = datetime.datetime.now()
    t_now = dt_now.time()
    t_night = datetime.time(hour=0,minute=0)
    t_twilight = datetime.time(hour=5,minute=45)
    t_morning = datetime.time(hour=7,minute=45)
    t_end = datetime.time(hour=10,minute=0)
    if t_night <= t_now < t_twilight:
        return "night"
    elif t_twilight <= t_now < t_morning:
        return "twilight"
    elif t_morning <= t_now < t_end:
        return "morning"
    else:
        return "off"

def play_audio (time_cycle):
    randomfile = random.choice(os.listdir("/home/pi/music/nature-sounds/" + time_cycle))
    file = '/home/pi/music/nature-sounds/' + time_cycle + '/' + randomfile
    print "playing track: " + randomfile
    cmd = 'omxplayer --vol -200 ' + file
    subprocess.call (cmd, shell=True)
    what_to_play()

def what_to_play():
    current_cycle = check_time()
    if current_cycle == "off" :
        print "sounds currently off - @{}".format(time.ctime())
        time.sleep(30)
        what_to_play()
    else:
        print "Now playing from " + current_cycle + " @{}".format(time.ctime())
        play_audio(current_cycle)

what_to_play()