im trying to create a program that will load a file (called lines.txt), add lines to it and will remove them, im using tkinter as a gui. i cannot however finish the add_line section as it always returns "NameError: global name is not defined' creating error when it has been defined.", it is defined on line 29 as listbox = Listbox(root), the section it is failing at is in def Add_Barcode(self): in def Add(self): on line 95. listbox.insert(END, term)
from tkinter import Tk, Frame, Menu
import sys, time, math
from tkinter import *
try:
root = Tk()
root.wm_title("barcode manager")
root.geometry("250x150+300+300")
class Example(Frame):
def __init__(self, parent):
Frame.__init__(self, parent)
self.parent = parent
self.initUI()
def initUI(self):
self.parent.title("Registered Barcodes.")
menubar = Menu(self.parent)
self.parent.config(menu=menubar)
fileMenu = Menu(menubar)
fileMenu.add_command(label="Add Barcode", command=self.Add_Barcode)
fileMenu.add_command(label="Save", command=self.Save)
fileMenu.add_command(label="Exit", command=self.onExit)
menubar.add_cascade(label="File", menu=fileMenu)
listbox = Listbox(root)
listbox.pack(fill=BOTH, expand=1)
def Popup_Menu():
menu = Menu(root, tearoff=0)
menu.add_command(label="Edit", command=lambda:print("hello"))
menu.add_command(label="Delete", command=lambda:print(DeleteSelection(self)))
def popup(event):
menu.post(event.x_root, event.y_root)
listbox.bind("<Button-3>", popup)
Popup_Menu()
def get_lines():
lines = open('lines.txt', 'r')
for line in lines:
barcode, text = line.split(',')
text.strip('\n')
line = ': '.join(str(x) for x in ("GTIN #", barcode, text))
listbox.insert(END, line)
get_lines()
def DeleteSelection(self) :
items = listbox.curselection()
pos = 0
for i in items :
idx = int(i) - pos
listbox.delete( idx,idx )
pos = pos + 1
def Add_Barcode(self):
import tkinter as tk
nroot = Toplevel()
nroot.wm_title("Add a barcode")
textbox_lbl = Label(nroot, text="text")
textbox_lbl.pack(side=LEFT, fill=Y)
textbox = Entry(nroot, bd=2)
textbox.pack(side=LEFT, fill=Y)
textbox.pack(anchor=CENTER)
barcode_lbl = Label(nroot, text="barcode")
barcode_lbl.pack(side=LEFT, fill=Y)
barcode = Entry(nroot, bd=2)
barcode.pack(side=LEFT, fill=Y)
barcode.pack(anchor=CENTER)
def Add(self):
nonlocal textbox
nonlocal barcode
text = textbox.get()
barcode = barcode.get()
nroot.destroy()
a = 0
for item in barcode:
a += 1
if a == 7:
try:
barcode = Get_Check_Digit()
barcode = int(barcode)
print(barcode)
term = ': '.join(str(x) for x in ("GTIN #", barcode, text))
print(term)
listbox.insert(END, term)
except ():
error = Toplevel()
error.wm_title("Error")
error_label = Label(error, text="please enter only numbers.")
error_label.pack(side=TOP, fill=X)
else:
error = Toplevel()
error.wm_title("Error")
error_label = Label(error, text="Error")
error_label.pack(side=TOP, fill=X)
error_label1 = Label(error, text="please enter 7 digits")
error_label1.pack(side=TOP, fill=X)
time.sleep(5)
error.destroy()
def Get_Check_Digit():
checklist = []
number = 1
nonlocal barcode
for item in barcode:
checkitem = int(item) * int(number)
checklist.append(checkitem)
if number == 3:
number = 1
elif number == 1:
number = 3
checklist = sum(checklist)
def roundup(x):
return int(math.ceil(x / 10.0)) * 10
check_digit = roundup(checklist)
check_digit -= checklist
num = "".join(str(x) for x in (barcode, check_digit))
return num
btn = Button(nroot, text="Add", command=lambda:Add(self))
btn.pack(side=BOTTOM, fill=Y)
def Save(self):
global listbox
for item in listbox:
print(item)
def onExit(self):
root.destroy()
sys.exit()
app = Example(root)
root.mainloop()
except ():
pass
