part.py 文件源码

def adjust_content_type(content_type, body=None, filename=None):
    """Adjust content type based on filename or body contents
    """
    if filename and str(content_type) == 'application/octet-stream':
        # check if our internal guess returns anything
        guessed = _guess_type(filename)
        if guessed:
            return guessed

        # our internal attempt didn't return anything, use mimetypes
        guessed = mimetypes.guess_type(filename)[0]
        if guessed:
            main, sub = fix_content_type(
                guessed, default=('application', 'octet-stream'))
            content_type = ContentType(main, sub)

    if content_type.main == 'image' and body:
        sub = imghdr.what(None, body)
        if sub:
            content_type = ContentType('image', sub)

    elif content_type.main == 'audio' and body:
        sub = audio._whatsnd(body)
        if sub:
            content_type = ContentType('audio', sub)

    return content_type