def obspytime2vtime( obspytime ):
    """
    Converts UTCdatetime (an obspy object) to a valve time.
    
    Parameters
    ----------
    obspytime: list
        List of UTCdatetime objects.
        
    Outputs
    ---------
    vtime: list
        List of strings of valve times (yyyymmddHHMMSS).
        
    """
    vtime = [nowtime.strftime('%Y%m%d%H%M%S') for nowtime in obspytime]   
    return vtime