python程序中的全局名称错误[关闭]

我有这样的代码：

#!/usr/bin/python
# -*- coding: utf-8 -*-

import tkMessageBox as box
import time                                                     
from tkFileDialog   import askopenfilename,asksaveasfilename    
import pcapy                       
from impacket import ImpactDecoder, ImpactPacket                
import thread                                                   
import sys                                                      
import tkMessageBox      
from Tkinter import Tk, Text, BOTH, W, N, E, S, StringVar, END, Listbox
from ttk import Frame, Button, Label, Style


class Program(Frame):

    def __init__(self, parent):
        Frame.__init__(self, parent)   

        self.parent = parent

        self.initUI()

    def initUI(self):

        self.parent.title("Wąchacz")
        self.style = Style()
        self.style.theme_use("default")
        self.pack(fill=BOTH, expand=1)

        devices = pcapy.findalldevs()
        acts = devices
        lb = Listbox(self)
        for i in acts:
            lb.insert(END, i)

        self.columnconfigure(1, weight=1)
        self.columnconfigure(3, pad=7)
        self.rowconfigure(3, weight=1)
        self.rowconfigure(5, pad=7)

        lbl = Label(self, text="Wybierz interface:")
        lbl.grid(sticky=W, pady=4, padx=5)

        lb.bind("<<ListboxSelect>>", self.onSelect)    

        lb.grid(row=1, column=0, columnspan=2, rowspan=4, 
            padx=5, sticky=E+W+S+N)

        self.var = StringVar()

        self.columnconfigure(1, weight=1)
        self.columnconfigure(3, pad=7)
        self.rowconfigure(3, weight=1)
        self.rowconfigure(5, pad=7)


        abtn = Button(self, text="Start", command=self.start)
        abtn.grid( row=1, column=3)

        bbtn = Button(self, text="Stop", command=self.threadinterrupt)
        bbtn.grid(row=2, column=3, pady=4)

        cbtn = Button(self, text="Otwórz", command=self.OpenFile)
        cbtn.grid(row=3, column=3, pady=4)

        dbtn = Button(self, text="Zapisz", command=self.SaveFile)
        dbtn.grid(row=4, column=3, pady=4)

        ebtn = Button(self, text="O programie...", command=self.onAbout)
        ebtn.grid( row=5, column=3, pady=4)

        fbtn = Button(self, text="Zamknij", command=self.quitGui)
        fbtn.grid( row=5, column=0, pady=10)


    def start(self):
        try:
            thread.start_new_thread(eth_addr,())
        except (KeyboardInterrupt, SystemExit):
               cleanup_stop_thread();
               sys.exit()   

    def threadinterrupt(self):
        thread.interrupt_main()


    def OpenFile(self):
        name = askopenfilename(filetypes=[("Pliki PCAP","*.pcap")],title="Otwórz plik pcap")

    def SaveFile(self):
        asksaveasfilename(filetypes=[("Pliki PCAP","*.pcap")],title="Zapisz plik pcap")                               

    def quitGui(self):
        answer = box.askquestion('wyjscie', "Napewno chcesz wyjść? ")
        if answer == 'yes':
            self.quit()


    def onAbout(self):
       box.showinfo("O programie", '''monitorowanie ruchu sieciowego''')

    def onSelect(self, val):

        interface1 = val.widget
        idx = interface1.curselection()
        value = interface1.get(idx)   

        self.var.set(value)


    def eth_addr(a) :
        b = "%.2x:%.2x:%.2x:%.2x:%.2x:%.2x" % (ord(a[0]) , ord(a[1]) , ord(a[2]), ord(a[3]), ord(a[4]) , ord(a[5]))
        return b
        global interface1
        interface1 =  str(var1.get())

        try:
            s = socket.socket( socket.AF_PACKET , socket.SOCK_RAW , socket.ntohs(0x0003))
        except socket.error, msg:
            print 'Kod błędu : ' + str(msg[0]) + ' Wiadomość ' + msg[1]
            sys.exit()

        while True:
            packet = s.recvfrom(interface1 , 65536, True, 1000)

        packet = packet[0]

        eth_length = 14

        eth_header = packet[:eth_length]
        eth = unpack('!6s6sH' , eth_header)
        eth_protocol = socket.ntohs(eth[2])
        print 'Docelowy adres MAC : ' + eth_addr(packet[0:6]) + ' Źródłowy adres MAC : ' + eth_addr(packet[6:12]) + ' Protokół : ' + str(eth_protocol)

        if eth_protocol == 8 :
            ip_header = packet[eth_length:20+eth_length]

                iph = unpack('!BBHHHBBH4s4s' , ip_header)

                version_ihl = iph[0]
                version = version_ihl >> 4
                ihl = version_ihl & 0xF

                iph_length = ihl * 4

                ttl = iph[5]
                protocol = iph[6]
                s_addr = socket.inet_ntoa(iph[8]);
                d_addr = socket.inet_ntoa(iph[9]);

                print 'Wersja : ' + str(version) + ' Długość nagłówka IP : ' + str(ihl) + ' TTL : ' + str(ttl) + ' Protokół : ' + str(protocol) + ' Adres źródłowy : ' + str(s_addr) + ' Adres docelowy : ' + str(d_addr)


    if protocol == 6 :
        t = iph_length + eth_length
                tcp_header = packet[t:t+20]

                tcph = unpack('!HHLLBBHHH' , tcp_header)

                source_port = tcph[0]
                dest_port = tcph[1]
                sequence = tcph[2]
                acknowledgement = tcph[3]
                doff_reserved = tcph[4]
                tcph_length = doff_reserved >> 4

                print 'Port źródłowy : ' + str(source_port) + ' Port docelowy : ' + str(dest_port) + ' Numer sekwencji : ' + str(sequence) + ' Potwierdzenie : ' + str(acknowledgement) + ' Długość nagłówka TCP : ' + str(tcph_length)

                h_size = eth_length + iph_length + tcph_length * 4
                data_size = len(packet) - h_size
                data = packet[h_size:]

                print 'Dane : ' + data

    elif protocol == 1 :
                u = iph_length + eth_length
                icmph_length = 4
                icmp_header = packet[u:u+4]


                icmph = unpack('!BBH' , icmp_header)

                icmp_type = icmph[0]
                code = icmph[1]
                checksum = icmph[2]

                print 'Typ : ' + str(icmp_type) + ' Kod : ' + str(code) + ' Suma kontrolna : ' + str(checksum)

                h_size = eth_length + iph_length + icmph_length
                data_size = len(packet) - h_size


                data = packet[h_size:]

                print 'Dane : ' + data

    elif protocol == 17 :
                u = iph_length + eth_length
                udph_length = 8
                udp_header = packet[u:u+8]


                udph = unpack('!HHHH' , udp_header)

                source_port = udph[0]
                dest_port = udph[1]
                length = udph[2]
                checksum = udph[3]

                print 'Port źródłowy : ' + str(source_port) + ' Port docelowy : ' + str(dest_port) + ' Długość : ' + str(length) + ' Suma kontrolna : ' + str(checksum)

                h_size = eth_length + iph_length + udph_length
                data_size = len(packet) - h_size


                data = packet[h_size:]

                print 'Dane : ' + data

    else :
                print 'Protokół inny niż TCP/UDP/ICMP'

        print


def main():

    root = Tk()
    root.geometry("350x300+300+300")
    app = Program(root)
    root.mainloop()  




if __name__ == '__main__':
    main()

但按下启动按钮后，我有一个追溯：

Tkinter回调中的异常回溯（最近一次调用最后一次）：文件“/usr/lib/python2.7/lib-tk/Tkinter.py”，第1489行，在调用中返回self.func（* args）文件“示例 . py“，第80行，在start thread.start_new_thread（eth_addr，（））NameError：未定义全局名称'eth_addr'

有人可以帮我解决这个全局名称问题吗？