CODEWITHSUNDEEP
pythontkinter
Unknown
Unknown

Reputation: 1

Am I calling the function wrong?

I'm working with OOP, and I ran into a problem where when I call the method inside a class by using tkinter command it gives me an error.

I've tried different ways of calling the method but I'm stuck.

class ToDoList():
    def __init__(self):
        self.tasks = []

    def update_listbox(self):
        self.clear()
        for task in self.tasks:
            box_tasks.insert("end", task)

    def clear(self):
        box_tasks.insert("end", task)

    def add(self):
        task=txt_input.get()
        if task !=" ":
            tasks.append(task)
            self.update_listbox()
        else:
            display["text"]=("Input a task")

tkinter command call:

add=tk.Button(root, text="Add", fg="DarkOrchid3", bg="blanched almond", command=ToDoList.add)
add.pack(pady=5, ipadx=15)

txt_input=tk.Entry(root, width=25)
txt_input.pack(pady=15)

error:

TypeError: add() missing 1 required positional argument: 'self'

This is the error, I understand that it should be defined but I don't really know what it means by it...

Upvotes: 0

Views: 73

Answers (2)

Harsha Biyani
Harsha Biyani

Reputation: 7268

Try by creating object for class ToDoList(). As class functions can be accessed from object of that class.

add=tk.Button(root, text="Add", fg="DarkOrchid3", bg="blanched almond", command=ToDoList().add)

Upvotes: 0

khelwood
khelwood

Reputation: 59114

add is an instance method and you don't instantiate ToDoList. If you make an instance of ToDoList, you can pass that instance's .add method.

todo = ToDoList()
add = tk.Button(root, text="Add", fg="DarkOrchid3", bg="blanched almond", command=todo.add)

Upvotes: 1

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