TypeError: generatecode() takes 0 positional arguments but 1 was given

Question

I have the code below:

from tkinter import *

class Window(Frame): 
    def __init__(self, master = None):
        Frame.__init__(self, master)
        self.master = master
        self.init_window()

    
    def init_window(self):
        self.master.title("COD:WWII Codes")
        self.pack(fill=BOTH, expand=1)
        codeButton = Button(
                        self, 
                        text="Generate Code", 
                        command=self.generatecode
                     )
        codeButton.place(x=0, y=0)

    def generatecode(self):
        f = open("C:/Programs/codes.txt", "r")
        t.insert(1.0. f.red())

root = Tk()
root.geometry("400x300")
app = Window(root)
root.mainloop()

Then, I got the error below:

TypeError: generatecode() takes 0 positional arguments but 1 was given

So, how can I solve the error?

Asked By: Jason Martin

||

Source

Answer 1

When you call a method on a class (such as generatecode() in this case), Python automatically passes self as the first argument to the function. So when you call self.my_func(), it’s more like calling MyClass.my_func(self).

So when Python tells you “generatecode() takes 0 positional arguments but 1 was given”, it’s telling you that your method is set up to take no arguments, but the self argument is still being passed when the method is called, so in fact it is receiving one argument.

Adding self to your method definition should resolve the problem.

def generatecode(self):
    pass  # Do stuff here

Alternatively, you can make the method static, in which case Python will not pass self as the first argument:

@staticmethod
def generatecode():
    pass  # Do stuff here

Answered By: Nikolas Stevenson-Molnar

Answer 2

I got the same error:

TypeError: test() takes 0 positional arguments but 1 was given

When defining an instance method without self and I called it as shown below:

class Person:
          # ↓↓ Without "self"     
    def test(): 
        print("Test")

obj = Person()
obj.test() # Here

So, I put self to the instance method and called it:

class Person:
            # ↓↓ Put "self"     
    def test(self): 
        print("Test")

obj = Person()
obj.test() # Here

Then, the error was solved:

Test

In addition, even if defining an instance method with self, we cannot call it directly by class name as shown below:

class Person:
            # Here     
    def test(self): 
        print("Test")

Person.test() # Cannot call it directly by class name

Then, the error below occurs:

TypeError: test() missing 1 required positional argument: ‘self’

But, if defining an instance method without self, we can call it directly by class name as shown below:

class Person:
          # ↓↓ Without "self"     
    def test(): 
        print("Test")

Person.test() # Can call it directly by class name

Then, we can get the result below without any errors:

Test

In detail, I explain about instance method in my answer for What is an "instance method" in Python? and also explain about @staticmethod and @classmethod in my answer for @classmethod vs @staticmethod in Python.

Answered By: Kai – Kazuya Ito

Answer 3

The most upvoted answer does solve this issue,

And just in case anyone is doing this inside of a jupyternotebook. You must restart the kernel of the jupyternotebook in order for changes to update in the notebook

Answered By: Greg Gompers

TypeError: generatecode() takes 0 positional arguments but 1 was given

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