How to Resolve the TypeError in Python: Missing Required Positional Argument nums

Learn how to fix the common `TypeError: missing 1 required positional argument: 'nums'` in Python, particularly when working with LeetCode problems. This guide breaks down both the error and the solution.
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Understanding the TypeError in Python

This issue can hinder your progress, but fear not! In this post, we'll explore the cause of this error and how to effectively resolve it.

The Problem: What Causes This Error?

The error occurs when a method in a class is called without the required arguments. In Python, when you define a method inside a class, the first parameter must always be self, which refers to the instance of the class itself. When the method is called directly from the class rather than from an instance of the class, Python expects the first argument (self) to be provided, as well as any other arguments defined.

The Code That Triggers the Error

Here's a snippet of code that results in the mentioned error:

[[See Video to Reveal this Text or Code Snippet]]

The Solution: How to Fix the Error

To resolve the issue, you have a couple of options. Let’s break them down.

Option 1: Remove self from the Method

This approach might work but isn't considered good practice. Here's how you can modify your method:

[[See Video to Reveal this Text or Code Snippet]]

In this corrected version, we've removed self from the parameters of removeDuplicates. While this will run without error, it’s not ideal.

Option 2: Properly Initialize the Class

The recommended way to resolve this issue is to create an instance of the Solution class before calling the method. This will ensure that self is automatically passed to the method:

[[See Video to Reveal this Text or Code Snippet]]

Advantages of Option 2

Readability: It's clear that removeDuplicates() is a method associated with an object of Solution.

Good Practice: This maintains the object-oriented structure of your code.

Future Expandability: If removeDuplicates depends on other attributes or methods of Solution, having a proper instance allows for more complex functionality in the future.

Conclusion

Feel free to explore more on LeetCode and practice your skills, armed with this knowledge to handle similar errors in the future!