What is overflow encountered in Python?
This warning occurs when you use the NumPy exp function, but use a value that is too large for it to handle. It's important to note that this is simply a warning and that NumPy will still carry out the calculation you requested, but it provides the warning by default.
What is a runtime warning?
Runtime warnings in libraries are a great way to notify your users that something unexpected has happened, or that an API is being used in an incorrect manner. There are a number of ways of handling this, from in-your-face assertion failures to easy-to-miss console logging.