How can I measure execution time of each test in large (500+) test suite for Django project

I'm working with a Django project that has quite large test suite based on builtin unittest. I wonder if there is a smart way to get execution time of each test (to spot long lasting ones). I found two projects on github that are adding such functionality but at the cost of adding additional inheritance for the test class - I would like to avoid modifying each test class in order to add execution time measurements. To clarify I'm not interested in detailed profiling such as provided by e.g. pytest-profiling.