local variable 's' referenced before assignment

This error occurs when a variable is used before it is assigned a value. It can occur in Python when a local variable is referenced before it is assigned a value in the function or block of code.

For example, consider the following code:

def test_function():
    print(s)
    s = "Hello world!"

In this code, the variable 's' is referenced in the print statement before it is assigned a value in the next line. This will result in the "local variable 's' referenced before assignment" error.

To fix this error, the variable should be assigned a value before it is referenced. For example:

def test_function():
    s = "Hello world!"
    print(s)

In this updated code, the variable 's' is assigned a value before it is referenced in the print statement, so the error will not occur.