绘图和计数器python无法获得结果

Question

要从pcap获取到plotly的目标端口结果，我无法获取到plotly图表的任何结果，但是如果我打印（dport）可以列出dport结果，python上有什么错误吗

from scapy.all import *
import plotly
from collections import Counter
ReadPacket = rdpcap("Subnet192.pcap")

dstPORT=[]
for pkt in ReadPacket:
   if pkt.haslayer("TCP"):
      try:
         ddport = pkt["TCP"].dport
      except:
         pass

cnt=Counter()
for TCP in dstPORT:
        cnt[ddport]+= 1

xData=[]
yData=[]
for ddport, count in cnt.most_common():
        xData.append(dport)
        yData.append(count)
plotly.offline.plot({
         "data":[plotly.graph_objs.Bar(x=xData, y=yData)])
          })