def safe_clean(text):
    from flask import Markup
    from bleach import clean
    tags = ['b','i','font','br']
    attrs = {
        '*':['style'],
        'font':['color']
    }
    styles = ['color']
    return Markup(clean(text,tags = tags,
                        attributes = attrs,
                        styles = styles))
自定义filter过滤器
