如何在Python脚本中解析和打印来自pymeter的API响应和错误代码？

如何在 python 脚本中解析和打印来自 pymeter 的 API 响应和错误代码？

PyMeter 是 jmeter 的 python 版本。 （pymeter 帮助文档 - https://pymeter.readthedocs.io/en/latest/api.html ）

我正在尝试获取 API 的性能统计数据 - https:// reqres.in/api/users?page=2 它给出以下响应。我可以使用 pymeter 采样器执行 api，但是无法找到任何有关如何解析 API 响应的帮助文档。

{"page":2,"per_page":6,"total":12,"total_pages":2,"data":[{"id":7,"email":"[email protected]","first_name":"Michael","last_name":"Lawson","avatar":"https://reqres.in/img/faces/7-image.jpg"},{"id":8,"email":"[email protected]","first_name":"Lindsay","last_name":"Ferguson","avatar":"https://reqres.in/img/faces/8-image.jpg"},{"id":9,"email":"[email protected]","first_name":"Tobias","last_name":"Funke","avatar":"https://reqres.in/img/faces/9-image.jpg"},{"id":10,"email":"[email protected]","first_name":"Byron","last_name":"Fields","avatar":"https://reqres.in/img/faces/10-image.jpg"},{"id":11,"email":"[email protected]","first_name":"George","last_name":"Edwards","avatar":"https://reqres.in/img/faces/11-image.jpg"},{"id":12,"email":"[email protected]","first_name":"Rachel","last_name":"Howell","avatar":"https://reqres.in/img/faces/12-image.jpg"}],"support":{"url":"https://reqres.in/#support-heading","text":"To keep ReqRes free, contributions towards server costs are appreciated!"}}

这是我的示例脚本 -

from unittest import TestCase
from pymeter.api.config import TestPlan, ThreadGroupWithRampUpAndHold
from pymeter.api.samplers import HttpSampler
from pymeter.api.reporters import HtmlReporter
from pymeter.api.postprocessors import JsonExtractor
from pymeter.api.assertions import ResponseAssertion

class TestTestPlanClass(TestCase):
    def __init__(self, *args, **kwargs):
      super(TestTestPlanClass, self).__init__(*args, **kwargs)
      print("TestTestPlanClass")

    @classmethod
    def setUpClass(cls):
        print("setUpClass")

    def test_case_1(self):
        json_extractor = JsonExtractor("variable", "args.data")

        # create HTTP sampler, sends a get request to the given url
        ra = ResponseAssertion().contains_substrings("data")
        http_sampler = HttpSampler("echo_get_request", "https://reqres.in/api/users?page=2", json_extractor)

        # create html reporter
        html_reporter = HtmlReporter()

        # create a thread group that will rump up 10 threads in 1 second and
        # hold the load for additional 10 seconds, give it the http sampler as a child input
        thread_group_main = ThreadGroupWithRampUpAndHold(1, 1, 1, http_sampler)

        # create a test plan with the required thread group
        test_plan = TestPlan(thread_group_main, html_reporter)

        # run the test plan and take the results
        stats = test_plan.run()

        self.assertLess(stats.sample_time_99_percentile_milliseconds, 2000)

    @classmethod
    def tearDownClass(cls):
        print("tearDownClass")
 

你可以在 PyMeter 中使用 JsonExtractor 后处理器解析 JSON 响应，然后使用响应断言或自定义逻辑访问提取的值。以下是如何执行此操作的方法：

1. 使用 JsonExtractor 提取值：

你已经在脚本中使用了 JsonExtractor ，但让我们对其进行调整以提取所需的值。例如，要提取第一个用户的电子邮件地址，可以使用以下 JSON 路径： $.data[0].email 。

json_extractor = JsonExtractor("user_email", "$.data[0].email")

这将创建一个名为“user_email”的变量，并在其中存储提取的值。

2. 在响应断言中访问提取的值：

你可以使用 ${} 语法在响应断言中访问提取的变量。例如，要断言第一个用户的电子邮件地址包含“reqres.in”，可以使用以下代码：

ra = ResponseAssertion().contains_substrings("${user_email}")

3. 在自定义逻辑中访问提取的值：

你也可以在 test_case_1 方法中访问提取的变量，例如：

# ... your existing code ...

stats = test_plan.run()

# Access the extracted value
extracted_email = stats.vars.get("user_email")
print(f"Extracted email: {extracted_email}")

# ... your assertion logic ...

完整脚本：

from unittest import TestCase
from pymeter.api.config import TestPlan, ThreadGroupWithRampUpAndHold
from pymeter.api.samplers import HttpSampler
from pymeter.api.reporters import HtmlReporter
from pymeter.api.postprocessors import JsonExtractor
from pymeter.api.assertions import ResponseAssertion

class TestTestPlanClass(TestCase):
    # ... your existing code ...

    def test_case_1(self):
        # Extract the email of the first user
        json_extractor = JsonExtractor("user_email", "$.data[0].email")

        # ... your existing code ...

        # create a thread group ...
        thread_group_main = ThreadGroupWithRampUpAndHold(1, 1, 1, http_sampler)

        # ... your existing code ...

        # run the test plan and take the results
        stats = test_plan.run()

        # Access the extracted value
        extracted_email = stats.vars.get("user_email")
        print(f"Extracted email: {extracted_email}")

        # Assert the extracted email contains "reqres.in"
        self.assertIn("reqres.in", extracted_email)

        # ... your other assertion logic ...

    # ... your existing code ...

错误代码：

要获取 API 响应的错误代码，可以使用 ResponseAssertion 并检查响应代码是否与预期值匹配。例如，要断言响应代码为 200（OK），可以使用以下代码：

ra = ResponseAssertion().assert_status_code(200)

你还可以使用 stats.response_code 属性在自定义逻辑中访问响应代码。