在python中单元测试是什么

def add(a, b):

    """return a + b

    Args:

        a (int): int

        b (int): int

    Returns:

        a + b

    Raises:

        AssertionError: if a or b is not integer

    """

    assert all([isinstance(a, int), isinstance(b, int)])

    return a + b

def test_add():

    assert add(1, 2) == 3

    assert isinstance(add(1, 2) , int)

    with pytest.raises(Exception):    # test exception

        add('1', 2)

py.test test_mod.py   # run tests in module

py.test somepath      # run all tests below somepath

py.test -q test_file_name.py    # quite输出

py.test -s test_file_name.py    # -s参数可以打印测试代码中的输出，默认不打印，print没结果

py.test test_mod.py::test_func  # only run tests that match the "node ID",

py.test test_mod.py::TestClass::test_method  # run a single method in