问python中的pdfdump不能使用scapy

EN

    #!/bin/bash/python3
from scapy3k.all import *``
import subprocess
import os

def ifac111():
    pkts = sniff(filter="tcp", iface="tun0", count=100)
    inp = input('want to see a \'pdfdump?\' \n Y/N--> ')
    fag = pkts.summary()
    print('-' * 60)
    what_df = pkts.show()
    print("^^^ Here you got {} packets {}.".format("100", "scanned"))
    print("The {} ones are {} and second ones are just {} command".format("first", "summary", "show" ))
    print(inp)
    if inp == 'Y':
        pkts[0].pdfdump()
    else:
        print("got ya \f hex0")

while 1 > 0:
    SSS = input('enter your command\'s here:-> \t ') #\t moves 4 spaces
    if SSS == 'packets':

        ifac111()

         elif SSS == 'nworkscan':
         os.system('sudo nmap localhost/24')
    elif SSS == 'Virusscan':
        os.system('sudo chkrootkit')
     elif SSS == 'clear':
        subprocess.call('clear')

Traceback (most recent call last):
  File "scapy2.py", line 27, in <module>
    ifac111()
  File "scapy2.py", line 16, in ifac111
    pkts[0].pdfdump()
  File "/usr/local/lib/python3.6/dist-packages/scapy3k/packet.py", line 418, in pdfdump
    canvas = self.canvas_dump(**kargs)
  File "/usr/local/lib/python3.6/dist-packages/scapy3k/packet.py", line 428, in canvas_dump
    canvas = pyx.canvas.canvas()
NameError: name 'pyx' is not defined