人性化日期显示

datehum.py

@app.template_filter('datetimeformat')
def timesince(dt, default="刚刚"):
    """
    返回人性化，时间字符串。e.g.:
    3 天前, 5小时前 etc.
    """
    now = datetime.utcnow()
    diff = now - dt
    periods = (
        (diff.days / 365,  "year"),
        (diff.days / 30,  "月"),
        (diff.days / 7, "周"),
        (diff.days, "天"),
        (diff.seconds / 3600,  "小时"),
        (diff.seconds / 60, "分钟"),
        (diff.seconds,  "秒"),
    )
    
    flag=0
    for period, plural in periods:
        flag+=1
        if period:
           return  default  if flag == 7 and period<45 else "%d%s前" % (period, plural)

    return default