用python的dpkt库解析离线网络数据包，并用ChartDirector库将网络数据包数据按时序关系(横轴为时间，纵轴为数据包大小)绘图，便于网络分析,Parsing library with python s dpkt off-line network packet, and use ChartDirector library network packet data according to temporal relationship (the horizontal axis is tim