Resolving Python AssertionError: Steps for Debugging Assertions

Resolving Python AssertionError: Steps for Debugging Assertions

Would you like to understand everything about exceptions in Python? You are at the right place to learn, because today we have to share knowledge on Python AssertionErrort with different examples to clear its fundamental idea. Different steps are mentioned in detail also with the author’s recommendations for beginners. Must read it from start to end if you want to cover the AssertionError topic in Python.

I know your situation! Don’t worry

You are searching on the Internet to get a solution for the AssertionError exception that was raised in your Python code. You do not need to worry, because I have published this post for you guys to share my experience as well as knowledge that I have. Everything with proper examples shared with you, I didn’t want to hide anything from you.

I recommend you to read this article which is full of information related to Python AssertionError which is the famous exception that arose while working on your project, mostly it raised due to the failure of an assert statement.

Why do you get this error, you know?

You have used an assert statement in your code and got an AssertionError Exception. I want to share your case here, your concept will be clear

assert function takes two parameters, one is a condition or expression and another is an optional value that shows when the condition is false. When the first parameter that is condition is true, you will not get any error, if this condition becomes false you will get an assertion error and an optional value will return.

You need to analyze your code where you are making errors, just share it with me in case you are unable to find an error, and I will help you, don’t worry!

What is an assertion error in the facet of Python language?

AssertionError is raised when a condition is false with an assert statement. Assert statement is the special keyword used in Python language to check a condition, whether it is false or true. If this condition is true, an interpreter goes to the next statement for execution. If it return false hten it go to optional paramter to execute stamten whcih cotnain useally a user frienldy error message.

Coding Example:

In this example,a value is 10, we want to check the condition if a value is 10 then you have to go to the next statement ( that shows the value). If a value is not equal to 1o, it means that the condition is false and it will show the next parameter that is “a value is not equal to 10”.

Step-by-Step Guide for Debugging Assertions

Would like to debug assertions in your Python program, here is step by step-by-step guide for beginners to understand properly with examples.

Enable Assertions

If you want to debug assertion error in your Python code, you should know that by default it’s enabling and disabling. By default in your Python system assertion is enabled which means that whenever the condition is written with an assert statement and a false, an exception will raise. But when you disable assertion checking, you will not get an error. You need to enable it if it is disabled.

You need to use -O command to disable assertion if you want, your Python executing command will be like this one:

When you run this command your Python file will be executed without showing an exception error,

Review the AssertionError Message

It is good practice to use the 2nd parameter in the assert statement, in the 2nd parameter you can give a useful message to identify the error. When it shows an assertion message in the console, you will be able to understand, what is the error about.

In this case, a message will show in the console saying the actual reason due to that, expectation is raising.

Identify the Failing Assertion

Next, you can go to your code where you used assert testament, by checking variables, expressions, their values, logic, etc you will be able to debug it easily.

Print Variable Values

Another good practice is to show the viable value with a print statement, which makes it easy to develop what is going on. What are the values of variables and what are expectations? Using a print statement to show the status of a variable it beocme easy to make a decision.

In this example, it shows the value of x and y in the terminal.

Evaluate Expressions Separately

It may be the case when you have a complex expression with an assert statement, here you need to make that complex into simpler parts, and then evaluate separately. For example,

When you evaluate the different experiences separately, you may get a specific assertion message for a specific expression, which beocme easy to debug.

Author Recommendation for you

As you know that different Python exception I have discussed with you in detail with proper examples. I want to share some recommendations for you while working on Python projects and handling different assertions. You need to use a simpler statement with an assert keyword and must write a 2nd optional parameters that show the error message in the console. Sometimes, it doesn’t show exceptions in the console, beginners disable it, but you need to enable it while finding the actual error point in the source code. These are the basic recommendations for beginners, keep learning and enjoying Python code writing.


In this post, Python AssertionError is discussed with different examples and also shared best recommendations for you to do. If you are facing an assertion error exception, I have shared a complete step-by-step strategy to find out its root.


Additional Resource

Different resources I have shared with you as additional resources. In this section, I want to share other resources with you to learn more about Python AssertionError with proper examples. Additional resources will help you to learn more, which will make you an experienced code writer.

Feedback and Comment

AssertionError is very easy to understand and manage in the program to manage your project’s different functionalities. Instructor guide will help you to understand in a better way. At the last, you can give your beneficial comments to improve this lesson. Our goal is to update this article in-depth to share beneficial information to users. Please share your thoughts and knowledge with me in the comments.

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