audiotools.py 文件源码

def get_mime_type(filename):
    """ Returns the MIME type associated with a particular audio file.
    """
    try:
        import magic
    except ImportError:
        if get_mime_type.warn:
            logger.warning('Python package "magic" could not be loaded, '
                'possibly because system library "libmagic" could not be '
                'found. We are falling back on our own heuristics.')
            get_mime_type.warn = False

        ext = os.path.splitext(filename)[1].lower()
        return {
            '.wav' : 'audio/x-wav',
            '.mp3' : 'audio/mpeg',
            '.flac' : 'audio/x-flac'
        }.get(ext, 'unknown')
    else:
        # Read off magic numbers and return MIME types
        mime_magic = magic.Magic(mime=True)
        ftype = mime_magic.from_file(filename)
        if isinstance(ftype, bytes):
            ftype = ftype.decode('utf-8')

        # If we are dealing with a symlink, read the link
        # and try again with the target file.  We do this in 
        # a while loop to cover the case of symlinks which
        # point to other symlinks
        current_filename = filename
        while ftype == 'inode/symlink':
            current_filename = os.readlink(current_filename)
            ftype = mime_magic.from_file(current_filename)
            ftype = ftype.decode('utf-8') if isinstance(ftype, bytes) else ftype

        return ftype