Question

尝试将大型（可能非常）不可解析的对象渲染到文件中供以后使用。

dill.dump(file)方没有投诉：

In [1]: import echonest.remix.audio as audio

In [2]: import dill

In [3]: audiofile = audio.LocalAudioFile("/Users/path/Track01.mp3")
en-ffmpeg -i "/Users/path/audio/Track01.mp3" -y -ac 2 -ar 44100 "/var/folders/X2/X2KGhecyG0aQhzRDohJqtU+++TI/-Tmp-/tmpWbonbH.wav"
Computed MD5 of file is b3820c166a014b7fb8abe15f42bbf26e
Probing for existing analysis

In [4]: with open('audio_object_dill.pkl', 'wb') as f:
   ...:     dill.dump(audiofile, f)
   ...:  

In [5]:

但是尝试加载.pkl文件：

In [1]: import dill

In [2]: with open('audio_object_dill.pkl', 'rb') as f:
   ...:     audio_object = dill.load(f)
   ...:

返回以下错误：

---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-2-203b696a7d73> in <module>()
      1 with open('audio_object_dill.pkl', 'rb') as f:
----> 2     audio_object = dill.load(f)
      3 

/Users/mikekilmer/Envs/GLITCH/lib/python2.7/site-packages/dill-0.2.2.dev-py2.7.egg/dill/dill.pyc in load(file)
    185     pik = Unpickler(file)
    186     pik._main_module = _main_module
--> 187     obj = pik.load()
    188     if type(obj).__module__ == _main_module.__name__: # point obj class to main
    189         try: obj.__class__ == getattr(pik._main_module, type(obj).__name__)

/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/pickle.pyc in load(self)
    856             while 1:
    857                 key = read(1)
--> 858                 dispatch[key](self)
    859         except _Stop, stopinst:
    860             return stopinst.value

/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/pickle.pyc in load_newobj(self)
   1081         args = self.stack.pop()
   1082         cls = self.stack[-1]
-> 1083         obj = cls.__new__(cls, *args)
   1084         self.stack[-1] = obj
   1085     dispatch[NEWOBJ] = load_newobj

TypeError: __new__() takes at least 2 arguments (1 given)

AudioObject比class object进行上述调用（来自SO answer）复杂得多（大），而且我不清楚是否需要发送通过dill的第二个参数，如果是这样，那个参数将是什么或如何判断任何酸洗方法对于这个特定对象是否可行。

稍微检查对象本身：

In [4]: for k, v in vars(audiofile).items():
...:     print k, v
...:

返回：

is_local False
defer False
numChannels 2
verbose True
endindex 13627008
analysis <echonest.remix.audio.AudioAnalysis object at 0x103c61bd0>
filename /Users/mikekilmer/Envs/GLITCH/glitcher/audio/Track01.mp3
convertedfile /var/folders/X2/X2KGhecyG0aQhzRDohJqtU+++TI/-Tmp-/tmp9ADD_Z.wav
sampleRate 44100
data [[0 0]
 [0 0]
 [0 0]
 ..., 
 [0 0]
 [0 0]
 [0 0]]

并且audiofile.analysis似乎包含一个名为audiofile.analysis.source的属性，其中包含（或显然指向）audiofile.analysis.source.analysis

Answer 1

在这种情况下，答案在于模块本身。

LocalAudioFile类提供（并且每个实例都可以使用它）它自己的save方法，通过LocalAudioFile.save或更可能the_audio_object_instance.save调用。

对于.mp3文件，LocalAudioFile实例由指向临时.wav文件的指针组成，该文件是.mp3的解压缩版本，以及在与基于互联网的Echonest API接口之后，从初始音频文件返回的一大堆分析数据。

LocalAudioFile.save调用shutil.copyfile(path_to_wave, wav_path)保存.wav文件，其名称和路径与链接到音频对象的原始文件相同，如果文件已存在则返回错误。它调用pickle.dump(self, f)将分析数据保存到调用初始音频对象文件的目录中的文件中。

LocalAudioFile对象只需通过pickle.load()重新引入。

这是一个iPython会话，其中我使用了dill，这是一个非常有用的包装器或接口，提供了大多数标准pickle方法以及更多：

audiofile = audio.LocalAudioFile("/Users/mikekilmer/Envs/GLITCH/glitcher/audio/Track01.mp3")

In [1]: import echonest.remix.audio as audio

In [2]: import dill
# create the audio_file object
In [3]: audiofile = audio.LocalAudioFile("/Users/mikekilmer/Envs/GLITCH/glitcher/audio/Track01.mp3")
en-ffmpeg -i "/Users/path/audio/Track01.mp3" -y -ac 2 -ar 44100 "/var/folders/X2/X2KGhecyG0aQhzRDohJqtU+++TI/-Tmp-/tmp_3Ei0_.wav"
Computed MD5 of file is b3820c166a014b7fb8abe15f42bbf26e
Probing for existing analysis
#call the LocalAudioFile save method
In [4]: audiofile.save()
Saving analysis to local file /Users/path/audio/Track01.mp3.analysis.en
#confirm the object is valid by calling it's duration method
In [5]: audiofile.duration
Out[5]: 308.96
#delete the object - there's probably a "correct" way to do this
in [6]: audiofile = 0
#confirm it's no longer an audio_object
In [7]: audiofile.duration
---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
<ipython-input-12-04baaeda53a4> in <module>()
----> 1 audiofile2.duration

AttributeError: 'int' object has no attribute 'duration'


#open the pickled version (using dill)
In [8]: with open('/Users/path/audio/Track01.mp3.analysis.en') as f:
   ....:     audiofile = dill.load(f)
   ....:     
#confirm it's a valid LocalAudioFile object
In [8]: audiofile.duration
Out[8]: 308.96

Echonest是一个非常强大的API，混音包提供了大量功能。有一小部分相关链接汇编here。

使用Dill在Load Object上的Python TypeError

1 个答案: