Nitpick: You do not want to add a commented-out import in a commit.
More seriously: Avoid star imports, particularly when importing from a third-party module (mpmath is), and especially particularly when modifying code that you are not a permanent maintainer of. Star imports tend to grow name conflicts as the imported module acquires new functions and classes, and Python does not tell you about such conflicts. Star imports also massively hamper static analysis tools such as pyflakes.