CODEWITHSUNDEEP
pythontkinter
coder_not_found
coder_not_found

Reputation: 200

why do I get Not defined error when using .winfo_exists (tkinter)

.winfo_exists() is supposed to return 1 or 0 depending on the existence of a widget

when I use .winfo_exists(), to check if a widget exists then I get the error: (Not defined)

name 'ErrorLabel' not defined

this is how I called the function:

    def delete_error(self):
        if self.ErrorLabel.winfo_exists() == 1:  # even with 'self.' removed same error occurs
            self.ErrorLabel.grid_forget()

(above is in a class)

I tried:

I don't understand why I get 'not defined' because I'm checking the existence of a object, so it doesn't have to be defined?

EDIT:

( the assignment of this variable depends if there is an error in input in the program so it doesn't always assign it,

that's why I need to check the existence of it when using grid_forget()

this is how it gets assigned:

 def raise_errors(self, flag):
    self.L5.grid_forget()
    if flag == 1 or flag == 3 or flag == 0:
        self.ErrorLabel = tk.Label(self.frame2, text="Error: Fill all the blanks !", fg='white', bg='red')
        self.ErrorLabel.grid(row=7, column=0, pady=10)
    elif flag == 2:
        self.ErrorLabel = tk.Label(self.frame2, text="Error: check ✔️ the correct answer ", fg='white', bg='red')
        self.ErrorLabel.grid(row=7, column=0, pady=10)

Upvotes: 1

Views: 384

Answers (1)

Delrius Euphoria
Delrius Euphoria

Reputation: 15098

What you could do is set ErrorLabel to be None and then check if it is None or not when calling delete_error(), if it is None then ignore, else find its existence.

def raise_errors(self, flag):
    self.ErrorLabel = None # Set to None
    self.L5.grid_forget()
    if flag == 1 or flag == 3 or flag == 0:
        self.ErrorLabel = tk.Label(self.frame2, text="Error: Fill all the blanks !", fg='white', bg='red')
        self.ErrorLabel.grid(row=7, column=0, pady=10)
    elif flag == 2:
        self.ErrorLabel = tk.Label(self.frame2, text="Error: check ✔️ the correct answer ", fg='white', bg='red')
        self.ErrorLabel.grid(row=7, column=0, pady=10)

Then your delete_error() would be:

def delete_error(self):
    if self.ErrorLabel is not None:    
        if self.ErrorLabel.winfo_exists():
            self.ErrorLabel.grid_forget()

This way it checks if the widget is made and if the widget is not made, then ignores.

I don't have code here to test this with, so you should also try to define self.ErrorLabel=None at __init__ too if first method doesn't work.

Alternatively, you could also use try and except to catch the error and then ignore it too:

def delete_error(self):
    try:
        if self.ErrorLabel.winfo_exists(): # Without setting self.ErrorLabel=None
            self.ErrorLabel.grid_forget()
    except NameError:
        pass

Upvotes: 1

Related Questions