Python - Variable in function not defined

Question

I'm trying to simulate a lottery and have a little problem with my functions. Here's what I'm trying to do:

1. run window1()
2. window1() --> destroy_window1() --> window2()
3. window2() --> destroy window2 or retry() --> window1()

The error occurs when I reach destroy_window1(), where i get the following message: "NameError: name 'e1' is not defined". How can I solve this problem?

I've read that you should pre-define the variables outside the functions. So, I tried to just put e1 = 1 etc., but then i get the message: "AttributeError: 'int' object has no attribute 'get'". Since it's an entry, I don't know how to pre-define it.

from tkinter import*
import random

Part1 = list(range(1,51))
Part2 = list(range(1,11))

Numbers = [0]*7

for n in range (5):
    Number = random.choice(Part1)

    Position = Part1.index(Number)
    del Part1[Position]

    Numbers[n] = Number


for i in range (2):
    Number = random.choice(Part2)

    Position = Part2.index(Number)
    del Part2[Position]

    Numbers[5+i] = Number

print (Numbers)


def destroy_window1():
    global Guess
    Guess = [e1.get(), e2.get(), e3.get(), e4.get(), e5.get(), e6.get(), e7.get()]
    master1.destroy()
    window2()

def retry():
    master2.destroy()
    window1()

def window1():

    master1 = Tk()
    master1.title('Lottery')
    Label(master1, text="Guess numbers:").grid(row=0)

    e1 = Entry(master1, width=2)
    e2 = Entry(master1, width=2)
    e3 = Entry(master1, width=2)
    e4 = Entry(master1, width=2)
    e5 = Entry(master1, width=2)
    e6 = Entry(master1, width=2)
    e7 = Entry(master1, width=2)


    e1.grid(row=0, column=1, padx=5)
    e2.grid(row=0, column=2, padx=5)
    e3.grid(row=0, column=3, padx=5)
    e4.grid(row=0, column=4, padx=5)
    e5.grid(row=0, column=5, padx=5)
    e6.grid(row=0, column=7, padx=5)
    e7.grid(row=0, column=8, padx=5)

    master1.grid_columnconfigure(6, minsize=20) # Creates an empty column (nr. 6) with width 20

    Button(master1, text='OK', command=destroy_window1).grid(row=3, column=3, sticky=W, pady=5)



    master1.mainloop()


def window2():

    master2 = Tk()
    master2.title('Check results')
    Label(master2, text="Drawn numbers:").grid(row=0, column=0, sticky=W)
    Label(master2, text="Your numbers:").grid(row=1, column=0, sticky=W)

    for n in range (7):
        Label(master2, text=Numbers[n]).grid(row=0, column=n+1, sticky=W, padx=5)

        if str(Numbers[n]) == Guess[n]:
            Label(master2, text=Guess[n], bg="green").grid(row=1, column=n+1, sticky=W, padx=5)
        else:
            Label(master2, text=Guess[n], bg="red").grid(row=1, column=n+1, sticky=W, padx=5)

    Button(master2, text='Quit', command=master2.destroy).grid(row=3, column=3, sticky=W, pady=5)
    Button(master2, text='Retry', command=retry).grid(row=3, column=4, sticky=W, pady=5)

    master2.mainloop ()

window1()

I can't vote up yet, thanks in advance!

Answer 1

The error occurs when I reach destroy_window1(), where i get the following message: "NameError: name 'e1' is not defined". How can I solve this problem?

The problem is that the destroy_window1() function doesn't know about the e1 variable, because e1 is defined within the window1() function (and its not global).

A simple fix is to put all the e variables into a list and pass that list as an argument to the destroy_window1() function. Make the list with a simple for loop, this not only solves your problem, but it also makes your code cleaner, easier to read, and easier to change it's functionality in future.

Like so:

def destroy_window1(e_list):
    global Guess
    Guess = []

    for e_item in e_list:
        Guess.append(e_item.get())

    master1.destroy()
    window2()

def window1():

    master1 = Tk()
    master1.title('Lottery')
    Label(master1, text="Guess numbers:").grid(row=0)

    e_list = []

    for i in range(7):
        temp_e = e1 = Entry(master1, width=2)
        temp_e.grid(row=0, column=i, padx=5)
        e_list.append(temp_e)

    master1.grid_columnconfigure(6, minsize=20) # Creates an empty column (nr. 6) with width 20

    Button(master1, text='OK', command=lambda :destroy_window1(e_list)).grid(row=3, column=3, sticky=W, pady=5)

    master1.mainloop()

Part of this solution involves a lambda function. This is because (as you may have noticed) the command option normally can't take arguments for the functions. The use of a lambda functions makes this possible. (Read up on Lambda Functions Here)

Answer 2

When you set e1=1 you are setting the variable e1 to 1 but the .get() function doesn't apply to an integer because the function has not been defined.