How to fix an attribute error when clearing an entry box

Question

While I was writing my code I stumbled over this error:

Exception in Tkinter callback
Traceback (most recent call last):
  File "C:Python33libtkinter__init__.py", line 1482, in __call__
    return self.func(*args)
  File "C:UsersBryanDesktopPython overhoorprogramma.py", line 18, in verify
    oentry.delete(0,END)
AttributeError: 'NoneType' object has no attribute 'delete'

I have already used the search function, but it didn’t seem to solve my problem. What I want to achieve is clearing an entry box.

# Maak een grafische interface / Create a graphical interface
gui = Tk()
gui.resizable(width=FALSE, height=FALSE)

# Verklaringen / Definitions
def verify():
    overify = antwoord.get()

    if overify == Nederlandsevertaling:
        ctypes.windll.user32.MessageBoxA(0, "Goed gedaan", "werkend", 1)
        oentry.delete(0,END)
    else:
            ctypefs.windll.user32.MessageBoxA(0, "Slecht gedaan", "Werkend", 1)
            oentry.delete()

antwoord = StringVar()
willekeurig = random.randint(0,9)

# Laad de database / Load the database
cnx = mysql.connector.connect(user='-', password='-', host='-', database='Overhoor')
cursor = cnx.cursor()

query = "SELECT FRwoord, NLwoord FROM unite8app1 WHERE id=%s"
cursor.execute(query, (willekeurig,))

for (FRwoord, NLwoord) in cursor:
    Fransevertaling = FRwoord
    Nederlandsevertaling = NLwoord

# Uiterlijk van het venster / Appearance of the window
gui.configure(background="white")
gui.title("Overhoorprogramma - Bryan")

# Grafische objecten / Graphical objects
style = ttk.Style()

olabel = ttk.Label(gui,text=Fransevertaling,font=("Times", 18), background="white").grid(row=0, column=0,padx=5, pady=5, sticky="W")
oentry = ttk.Entry(gui,textvariable=antwoord, font=("Times", 18)).grid(row=1, column=0,padx=5, pady=5)
obutton = ttk.Button(gui,text="Suivant", command = verify).grid(row=1, column=1,padx=5, pady=5)

# Stop de grafische interface
gui.mainloop()

oentry = ttk.Entry(gui,textvariable=antwoord, font=("Times", 18)).grid(row=1, column=0,padx=5, pady=5)
obutton = ttk.Button(gui,text="Suivant", command = verify).grid(row=1, column=1,padx=5, pady=5)

If you press obutton it’s supposed to clear the text in oentry. For this I tried to use:

oentry.delete(0,END)

And a couple of variations on .delete. Instead of clearing the textbox it gives back an error.

Exception in Tkinter callback
Traceback (most recent call last):
  File "C:Python33libtkinter__init__.py", line 1482, in __call__
    return self.func(*args)
  File "C:UsersBryanDesktopPython overhoorprogramma.py", line 18, in verify
    oentry.delete(0,END)
AttributeError: 'NoneType' object has no attribute 'delete'

Is there a fix?

Asked By: user3127288

||

Source

Answer 1

The grid method of every Tkinter widget works in-place (it always returns None).

In other words, every line like this:

olabel = ttk.Label(gui,text=Fransevertaling,font=("Times", 18), background="white").grid(row=0, column=0,padx=5, pady=5, sticky="W")

should be written like this:

olabel = ttk.Label(gui,text=Fransevertaling,font=("Times", 18), background="white")
olabel.grid(row=0, column=0,padx=5, pady=5, sticky="W")

with grid called on its own line.

Answered By: user2555451

Answer 2

I had the delete and insert statement preceding the actual "creation" of the Text box as such:

my_text.delete(1.0, tk.END)
my_text.insert(tk.INSERT, title)

my_text = tk.Text(frame2, width=40, height=10, font=("Helvetica", 18))
my_text.pack(pady=25, padx=25)

The creation coming first fixed it:

my_text = tk.Text(frame2, width=40, height=10, font=("Helvetica", 18))
my_text.pack(pady=25, padx=25)

my_text.delete(1.0, tk.END)
my_text.insert(tk.INSERT, title)

Answered By: Lod

How to fix an attribute error when clearing an entry box

Question:

Answers: