SyntaxWarning when fitting the model

[kopeckylukas]

Describe the bug
SyntaxWarning: "is not" with 'str' literal. Did you mean "!="

To Reproduce
Steps to reproduce the behavior:

1. Run the example code in readme files

Expected behavior
Results in SyntaxWarning: "is not" with 'str' literal. Did you mean "!=". This is because is not compares object identity, not value.

Environment (please complete the following information):

• OS: macOS 26.4
• Python version: 3.13.12
• Version of this software: [e.g. 1.0.0]
• Versions of required Python packages:
  • Numpy: 2.4.4
  • Scipy: 1.17.1
  • Scikit-learn: 1.8.0
  • Pandas: 3.0.1