Fix NameError: selective_scan_fn Not Defined

If you are working with Python and encounter the error NameError: name 'selective_scan_fn' is not defined, you are not alone. This error typically appears when a function name is used in your code but has not been properly imported or defined.

This article will explain why this error occurs, how to fix it, and provide practical examples to help you understand the issue better.

What Is NameError in Python?

In Python, a NameError occurs when the interpreter encounters a variable or function name that it does not recognize. This usually happens because the name was never defined or was not imported into the current scope.

The specific error NameError: name 'selective_scan_fn' is not defined means that Python is trying to use a function called selective_scan_fn but cannot find its definition anywhere in the program.

Why Does This Error Occur?

There are several reasons why you might see this error:

• The function selective_scan_fn is not imported from the module where it is defined.
• The function is not defined in your script.
• The function is defined in another file or module that was not loaded.
• There is a typo in the function name.

Understanding the root cause is important to fix the issue effectively.

How to Fix the NameError

Here are the main ways to resolve the error:

1. Import the Function

If selective_scan_fn is part of a library or custom module, you need to import it. For example, if the function exists in a module named my_module, you should import it like this:

from my_module import selective_scan_fn

This tells Python where to find the function definition.

2. Define the Function

If the function is not available in any module, you may need to define it yourself. Here is an example of how to define a simple version of selective_scan_fn:

def selective_scan_fn(input_data):
    # A simple placeholder