简述Python如何调用系统底层API播放wav文件

# Our raison d'etre - playing sounds
import pywintypes
import struct
import win32event
import win32com.directsound.directsound as ds
import os
WAV_HEADER_SIZE = struct.calcsize('<4sl4s4slhhllhh4sl')
def wav_header_unpack(data):
 '''解包wav文件头信息'''
 (riff, riffsize, wave, fmt, fmtsize, format, nchannels, samplespersecond, 
 datarate, blockalign, bitspersample, data, datalength) = struct.unpack('<4sl4s4slhhllhh4sl', data)
 if riff != b'RIFF' or fmtsize != 16 or fmt != b'fmt ' or data != b'data':
 raise ValueError
 wfx = pywintypes.WAVEFORMATEX()
 wfx.wFormatTag = format
 wfx.nChannels = nchannels
 wfx.nSamplesPerSec = samplespersecond
 wfx.nAvgBytesPerSec = datarate
 wfx.nBlockAlign = blockalign
 wfx.wBitsPerSample = bitspersample
 return wfx, datalength
# 播放wav文件，直到结束
sound_file = "音效-足球观众的欢呼声.wav"
fname = os.path.join(os.path.dirname(__file__), sound_file)
f = open(fname, 'rb')
# 读取/解包wav文件头
hdr = f.read(WAV_HEADER_SIZE)
wfx, size = wav_header_unpack(hdr)
d = ds.DirectSoundCreate(None, None)
d.SetCooperativeLevel(None, ds.DSSCL_PRIORITY)
sdesc = ds.DSBUFFERDESC()
sdesc.dwFlags = ds.DSBCAPS_STICKYFOCUS | ds.DSBCAPS_CTRLPOSITIONNOTIFY
sdesc.dwBufferBytes = size
sdesc.lpwfxFormat = wfx
buffer = d.CreateSoundBuffer(sdesc, None)
event = win32event.CreateEvent(None, 0, 0, None)
notify = buffer.QueryInterface(ds.IID_IDirectSoundNotify)
notify.SetNotificationPositions((ds.DSBPN_OFFSETSTOP, event))
buffer.Update(0, f.read(size))
buffer.Play(0)
win32event.WaitForSingleObject(event, -1)