The arguments a class object accepts are passed through a function called __init__()
. If you misspell this function in your class declaration, you’ll encounter a “TypeError: object() takes no arguments” error when you run your code.
In this guide, we talk about what this error means and why you may encounter it. We’ll walk through an example of this error to help you figure out how to fix it.
TypeError: object() takes no arguments
Objects of a class can optionally accept arguments. These arguments are used to set values within an object. Consider the following code:
class Employee: def __init__(self, name) self.name = name
The __init__method lets us assign a value for the “self.name” variable in our class. We can reference this variable in any method in our class.
The __init__ method is a special method. It is often called a constructor. The constructor method must be spelled correctly, otherwise you cannot pass any arguments into a statement where you declare an object of a class.
For reference, the __init__ method is spelled as:
Two underscores, followed by “init”, followed by two underscores.
The “TypeError: object() takes no arguments” error can also be caused by improper indentation. If you have spelled the __init__ method correctly, check to make sure you use consistent spaces and tabs in your class.
An Example Scenario
We’re going to create a program that tracks information about a product in an electronics store. To start, define a class. This class serves as the blueprint for our products:
class Product: def _init_(self, name, price, brand): self.name = name self.price = price self.brand = brand def show_price(self): print("The price of {} is ${}.".format(self.name, self.price))
Our class contains two methods. The first method is our constructor. This method defines all the values that objects of our class can store. The second method lets us view the price of a product.
Next, we’re going to create an object of our class:
george_foreman = Product("Fit Medium Health Grill", 39.99, "George Foreman")
This code creates an object for a George Foreman grill that is on sale at the electronics store. Next, we’re going to call our show_price()
method so that we can view the price of this product:
george_foreman.show_price()
Let’s run our code and see what happens:
Traceback (most recent call last): File "main.py", line 10, in <module> george_foreman = Product("Fit Medium Health Grill", 39.99, "George Foreman") TypeError: Product() takes no arguments
Our code returns an error message.
The Solution
To assign initial values to variables inside an object, you have to specify the values of those variables as arguments in the statement where an object is declared.
This only works if there is a valid __init__ method in an object. Otherwise, Python does not know how to treat the values you have specified as arguments. Without a special __init__ method, Python would not know which method should process the arguments.
In our code, we have declared an _init_ method (with one underscore on each side):
class Product: def _init_(self, name, price, brand):
This is not treated the same as __init__. To solve this error, we have to rename this method so that it uses the right syntax:
class Product: def __init__(self, name, price, brand): self.name = name self.price = price self.brand = brand
We’ve renamed our method to __init__. Let’s run our code and see if it works:
The price of Fit Medium Health Grill is $39.99.
Our code successfully tells us the price of the George Foreman grill.
TypeError: this constructor takes no arguments
The “TypeError: object() takes no arguments” error appears as “TypeError: this constructor takes no arguments” in Python 2.x.
This message tells us that we have made a mistake in defining our constructor. To solve this problem, make sure that you spell the __init__()
method correctly and that you use the correct indentation in the class that is causing the error.
Conclusion
The “TypeError: object() takes no arguments” error is raised when you do not declare a method called __init__ in a class that accepts arguments.
To solve this error, double-check your code to ensure that __init__()
is spelled correctly. The method should have two underscores on either side of the word “init”.
Now you’re ready to fix this common Python error like a professional!
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