I have an script in Python to test login on a web page.
My question : What are the alternatives to Behat compatible with Python?.
Thanks
Edit: This question got heavily edited after I answered so I am copying my out of scope comment into the answer: "It seems popular enough => github.com/behave/behave" 
Behat is a PHP library written in PHP. It would be too hard to get it to interface with your tests in Python.
On the other hand, I suggest looking up a Python-native BDD framework.
What are the alternatives to Behat for Python?