Count # asserts executed when running py.test

When I run py.test on file like

 test_a(): ...
 test_b(): ...

Py.test will say ... === 2 passed in 3.1415 seconds === .... I would like to know how many asserts have been tested, as one test_() function might have had multiple generated (for example in a for cycle, when testing new, faster implementation against slow, reference implementation of unit tested function.