测试过程中，同一个测试场景经常需要使用不同的测试数据来覆盖验证。在Behave中，我们可以通过Scenario Outlines来实现这种数据驱动的功能。

 1   Scenario Outline: search keyword from Baidu
 2     Given The index page of Baidu is ready
 3     When I input <keyword> in a search text field, and click search button
 4     Then The <keyword> should appear in page title
 5 
 6     Examples:
 7     | keyword |
 8     | python |
 9     | selenium |
10     | behave |

上面例子中，我们在When语句中指定了参数，并且在Examples中写出了变量的参数值。Behave在运行测试用例时，会将Examples中定义的参数值传入，每个参数值代表一个测试用例。

step实现代码如下：

 1 @given('The index page of Baidu is ready')
 2 def step_impl(context):
 3     context.driver.get("https://www.baidu.com")
 4     assert context.driver.find_element_by_id('kw') is not None
 5 
 6 @when('I input {keyword} in a search text field, and click search button')
 7 def step_impl(context, keyword):
 8     context.driver.find_element_by_id('kw').send_keys(keyword)
 9     context.driver.find_element_by_id('su').click()
10     sleep(2)
11 
12 @then('The {keyword} should appear in page title')
13 def step_impl(context, keyword):
14     assert keyword in context.driver.title

执行结果如下：

 1     When I input python in a search text field, and click search button # features/steps/tutorial.py:21
 2     Then The python should appear in page title                         # features/steps/tutorial.py:27
 3 
 4   @slow
 5   Scenario Outline: search keyword from Baidu -- @1.2                     # features/tutorial.feature:17
 6     Given The index page of Baidu is ready                                # features/steps/tutorial.py:16
 7     When I input selenium in a search text field, and click search button # features/steps/tutorial.py:21
 8     Then The selenium should appear in page title                         # features/steps/tutorial.py:27
 9 
10   @slow
11   Scenario Outline: search keyword from Baidu -- @1.3                   # features/tutorial.feature:18
12     Given The index page of Baidu is ready                              # features/steps/tutorial.py:16
13     When I input behave in a search text field, and click search button # features/steps/tutorial.py:21
14     Then The behave should appear in page title                         # features/steps/tutorial.py:27
15 
16 1 feature passed, 0 failed, 0 skipped
17 3 scenarios passed, 0 failed, 1 skipped
18 9 steps passed, 0 failed, 3 skipped, 0 undefined
19 Took 0m29.792s

更多资料可参考官方文档：https://behave.readthedocs.io/en/stable/tutorial.html#features