safestring.py 文件源码

def mark_safe(s):
    """
    Explicitly mark a string as safe for (HTML) output purposes. The returned
    object can be used everywhere a string or unicode object is appropriate.

    If used on a method as a decorator, mark the returned data as safe.

    Can be called multiple times on a single string.
    """
    if hasattr(s, '__html__'):
        return s
    if isinstance(s, bytes) or (isinstance(s, Promise) and s._delegate_bytes):
        return SafeBytes(s)
    if isinstance(s, (six.text_type, Promise)):
        return SafeText(s)
    if callable(s):
        return _safety_decorator(mark_safe, s)
    return SafeString(str(s))