Typeerror: missing 1 required positional argument:

Encountering “Typeerror: missing 1 required positional argument:“ error in your Python codes? and you don’t know how and why it occurs and how to fix it.

Worry no more! and read this article for you to understand this error.

In this article, we will discuss the possible causes of “Typeerror: missing 1 required positional argument:”, and provide solutions to resolve and troubleshoot the error.

But first, let’s Discuss what this Typeerror means.

What is Typeerror: missing 1 required positional argument:?

In Python, The error message “Typeerror: missing 1 required positional argument:” means that a function or method is being called with fewer arguments than it expects.

Specifically, this error message indicates that the function or method requires one or more arguments to be passed to it, but those arguments are not provided when the function is called.

Now let’s move to the causes of this Typeerror.

How does Typeerror: missing 1 required positional argument: occurs?

The Typeerror: missing 1 required positional argument: occurs when you try to call a function or instantiate an object without providing a required argument.

This error can occur for two primary reasons, such as:

Cause 1. A function is called without passing the required arguments:

The first cause why the “missing 1 required positional argument:” error occurs is when a function is called without passing the required arguments.

Functions in Python have a specific number of arguments that they expect to receive when called.

If one or more required arguments are not provided, the function will raise a TypeError indicating that a positional argument is missing.

Here is an example code that function is called without passing the required arguments:

def add_numbers(x):
    print(f"The result is {x}")
# Call the function without passing arguments
add_numbers()

In this example code, there is a function called add_numbers that takes one argument x, and prints a message that includes the value of x.

However, on the following line, the add_numbers function is called without passing any arguments:

add_numbers()

Because the add_numbers function expects one argument x, but none were provided, this will cause an error message indicating:

TypeError: add_numbers() missing 1 required positional argument: 'x'

Additionally, If a function in Python has multiple parameters, and you call the function without providing values for all of the required parameters, an error message will also raise.

For example, we will define a function that takes two parameters, adds them together, and prints the result:

def add_numbers(x, y):
    result = x + y
    print(f"The result is {result}")

# Call the function without passing arguments
add_numbers()

In this example, the add_numbers() function is called without passing any arguments.

Then Python will show an error message:

 TypeError: add_numbers() missing 2 required positional arguments: 'x' and 'y'

Because the function requires two arguments but none were provided.

Cause 2. An object is instantiated without passing the required arguments:

The second cause why “missing 1 required positional argument:” error occurs is when an object is instantiated without passing the required arguments.

In Python, you can create a class and define an __init__ method to initialize its attributes.

If you instantiate an object of the class without passing the required arguments, Python will raise the TypeError.

Here is an example that an object that is instantiated without passing the required arguments:

class Person:
    def __init__(self, name):
        self.name = name

person = Person()

In this example, the Person object is instantiated with the line person = Person(), no argument is passed to the __init__() method, that’s why it results in an error message stating:

TypeError: Person.__init__() missing 1 required positional argument: 'name'

Now let’s fix this error.

Typeerror: missing 1 required positional argument: – Solutions

Here is the alternative solution you can use to fix the “missing 1 required positional argument:” error along with examples of how to implement them:

Solution 1: Provide the required argument:

To fix the “missing 1 required positional argument:” error, you need to provide the required argument when calling the function or instantiating the object.

If you are calling a function, make sure to pass all required arguments in the correct order

Here is an example:

def add_numbers(x):
    print(f"The result is {x}")


# Call the function withpassing arguments
add_numbers(3)

Output

The result is 3

Alternatively, You can also consider making the arguments optional by providing default values in the function definition or constructor method signature.

For example:

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

# Call the function without passing arguments
greet()

# Output: Hello, World!

# Call the function with an argument
greet("John")

# Output: Hello, John!

Solution 2: An argument should be passed to the constructor method when instantiating the object:

To fix the “missing 1 required positional argument:” error you need to make sure to pass an argument to the constructor method when instantiating an object that requires arguments in its __init__method.

Just like the example below:

class Person:
    def __init__(self, name, age):
        self.name = name
        self.age = age

person = Person("John", 25)

Also, you can provide a default value for a function parameter or a constructor method parameter.

For example:

class Person:
    def __init__(self, name, age=0):
        self.name = name
        self.age = age
        
person1 = Person("Alice")  # age is not specified, so it defaults to 0
person2 = Person("Bob", 30)  # age is specified as 30

So these are the different solutions you may use to fix “Typeerror: missing 1 required positional argument:”.

Hoping that it helps you troubleshoot and resolve the error.

Here are the other fixed Python errors that you can visit, you might encounter them in the future.

• typeerror unsupported operand type s for str and int
• typeerror: object of type int64 is not json serializable
• typeerror: bad operand type for unary -: str

Conclusion

In conclusion, the Typeerror: missing 1 required positional argument: occurs when you try to call a function or instantiate an object without providing a required argument.

This error can occur for two primary reasons, such as:

• A function is called without passing the required arguments
• An object is instantiated without passing the required arguments

To solve this error, you need to provide the required argument to the function or constructor method and pass all required arguments in the correct order.

You can also consider making the arguments optional by providing default values.

By following the given solution, surely you can fix the error quickly and proceed to your coding project again.

I hope this article helps you to solve your problem regarding a Typeerror stating “missing 1 required positional argument:”.

We’re happy to help you.

Happy coding! Have a Good day and God bless.

John Paul Blauro

Programmer & Technical Writer at PIES IT Solution

John Paul Blauro is a programmer and writer at PIES IT Solution, author of 55 Python error-fix tutorials at itsourcecode.com. Specializes in Python TypeError debugging (str/int type errors, unsupported operand types, iterable-related issues) and AttributeError debugging (NoneType, dict/list/series object attribute errors) for developers and BSIT students.

Expertise: Python · Python TypeError · Python AttributeError · Type Debugging · Error Handling  · View all posts by John Paul Blauro →