How to fix TypeError: takes 0 positional arguments but 1 was given

When working with Python functions and classes, you might see the following error:

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

This error usually occurs when you call and pass an argument to a function that accepts 0 arguments.

There are two possible reasons why this error happens:

1. Your function accepts 0 arguments, but you pass it an argument when calling
2. You specify a class method without the self parameter

The following tutorial shows how to fix this error in both scenarios.

Note: arguments are called parameters when you specify them in the function header.

1. The function accepts 0 arguments

Suppose you have a function named greet() that has no parameter.

You then called the function and pass it an argument as shown below:

def greet():
    print("Hello World!")

greet("John")  # ❌

Python tries to send the argument John to the greet() function, but the function takes 0 arguments so the error occurs:

Traceback (most recent call last):
  File "main.py", line 8, in <module>
    greet("John")
TypeError: greet() takes 0 positional arguments but 1 was given

To fix this error, you need to remove the argument when you call the function, or you can specify parameters for the function as follows:

# 1. Remove the argument from the function call
def greet():
    print("Hello World!")

greet()  # Hello World!

# 2. Add parameter to the function
def greet(name):
    print(f"Hello {name}!")

greet("John")  # Hello John!

You’ll also get this error when you pass too many arguments to a function.

In the code below, the greet() function takes one argument but you give it two:

def greet(name):
    print(f"Hello {name}!")

greet("John", 29)
# TypeError: greet() takes 1 positional argument but 2 were given

When the function takes one argument, you need to pass it one argument.

2. A class method without the self parameter

This error also happens when you specify a class method without the self parameter.

Suppose you have the create a class named Human that has the following definition:

class Human:
    def talk():
        print("Talking")

Next, you instantiate an object from the class and call the talk() method:

person = Human()
person.talk()  # ❌

Output:

TypeError: Human.talk() takes 0 positional arguments but 1 was given

This error occurs because Python internally passes the class instance (the object itself) whenever you call a method of that class.

To resolve this error, you need to specify self as the parameter of all methods in your class even when you didn’t need it:

class Human:
    def talk(self):
        print("Talking")

person = Human()
person.talk()  # Talking

This time, we didn’t get any error because the talk() method accepts the self argument that gets passed automatically when you call it.

To conclude, the error TypeError: method() takes 0 positional arguments but 1 was given occurs when you pass one argument to a function that doesn’t take any.

You can fix this error by specifying the parameters required by the function, or you can remove the argument when calling that function.

I hope this tutorial is helpful. Enjoy coding! 👍