'NoneType' object has no attribute 'get' | Python GUI

Question

So I'm writing a simple Python GUI program to generate random numbers and keep getting this error: 'NoneType' object has no attribute 'get'

def ButClick():
    try:
        MinNum = int (txt1.get())
        MaxNum = int (txt2.get())
        Num = int (txt3.get())
    except ValueError:
        messagebox.showerror("ValueError", "Error! Invalid numbers")
    else:
        Nums = ''
        if MinNum <= MaxNum:
            i = 0
            while i < Num:
                numOne = randint(MinNum,MaxNum)
                Nums = Nums + ":" + str(numOne)
                i += 1
            scr.insert(INSERT, str(Nums) + "\n")
        else:
            messagebox.showerror("NumError!!", "Error! Invalid Numbers!")
    pass

root = Tk()
root.title("Random is so random :)")

lb1 = Label(root, text = "Min number").grid(
    row = 0,
    column = 0,
    pady = 10,
    padx = 10)

txt1 = Entry(root, width = 30).grid(
    row = 0,
    column = 1,
    pady = 10,
    padx = 10)

lb2 = Label(root, text = "Max number").grid(
    row = 1,
    column = 0,
    pady = 10,
    padx = 10)

txt2 = Entry(root, width = 30).grid(
    row = 1,
    column = 1,
    pady = 10,
    padx = 10)

lb3 = Label(root, text = "number").grid(
    row = 2,
    column = 0,
    pady = 10,
    padx = 10)

txt3 = Entry(root, width = 30).grid(
    row = 2,
    column = 1,
    pady = 10,
    padx = 10)

but = Button(root, width = 15, height = 2, text = "Generate", command = ButClick).grid(
    row = 3,
    column = 0,
    columnspan = 2,
    pady = 10,
    padx = 10)

scr = scrolledtext.ScrolledText(root, height = 10).grid(
    row = 4,
    column = 0,
    columnspan = 2,
    pady = 10,
    padx = 10)

How can I fix it? Maybe its because I need to use the older version of Python? I tried to install python 3.7.3 version via terminal but it was in vain. I watched other questions on this topic but couldn't find any specifically on attribute .get

Answer 1

grid() does not return anything, which is why all your variables like txt2 and lb1 end up as None, hence the error. I believe what you want to do is:

txt1 = Entry(root, width = 30)
txt1.grid(
    row = 0,
    column = 1,
    pady = 10,
    padx = 10)

Of course same goes for all other UI elements. Notice how the code first creates an element and stores it in a variable, and only then, separately, positions the element in the grid.