pytest测试用例编写----参数化测试（Parametrized Tesing）

def test_add_1():
    """tasks.get() using id returned from add() works."""
    task = Task('breathe', 'BRIAN', True)
    task_id = tasks.add(task)
    t_from_db = tasks.get(task_id)
    # everything but the id should be the same
    assert equivalent(t_from_db, task)


def equivalent(t1, t2):
    """Check two tasks for equivalence."""
    # Compare everything but the id field
    return ((t1.summary == t2.summary) and
            (t1.owner == t2.owner) and
            (t1.done == t2.done))


@pytest.fixture(autouse=True)
def initialized_tasks_db(tmpdir):
    """Connect to db before testing, disconnect after."""
    tasks.start_tasks_db(str(tmpdir), 'tiny')
    yield
    tasks.stop_tasks_db()

1.新建的Task对象，其id会被置为None，只有在发生数据库交互之后其id才会被填入相应的值。

2.equivalent()方法检查id之外的所有属性是否相等

3.autouse的fixture能确保数据库可访问

运行结果：

 

 @pytest.mark.parametrize(argnames, argvalues)装饰器达到批量传送参数的目的

@pytest.mark.parametrize('task',
                         [Task('sleep', done=True),
                          Task('wake', 'brian'),
                          Task('breathe', 'BRIAN', True),
                          Task('exercise', 'BrIaN', False)])
def test_add_2(task):
    """Demonstrate parametrize with one parameter."""
    task_id = tasks.add(task)
    t_from_db = tasks.get(task_id)
    assert equivalent(t_from_db, task)

parametrize()的第一个参数是用逗号分隔的字符串列表'task'；第二个参数是一个值列表‘Task对象列表’，pytest会对每个task做测试，并分别报告每一个测试用例结果。

 

 将parametrize()的task对象列表替换为几组键值对

@pytest.mark.parametrize('summary, owner, done',
                         [('sleep', None, False),
                          ('wake', 'brian', False),
                          ('breathe', 'BRIAN', True),
                          ('eat eggs', 'BrIaN', False),
                          ])
def test_add_3(summary, owner, done):
    """Demonstrate parametrize with multiple parameters."""
    task = Task(summary, owner, done)
    task_id = tasks.add(task)
    t_from_db = tasks.get(task_id)
    assert equivalent(t_from_db, task)

运行结果：