如何在Python脚本中解析并打印PyMeter的API响应与错误码？

问题说明 #

使用PyMeter对https://reqres.in/api/users?page=2执行性能测试时，已能成功调用API，但需要实现解析并打印API响应内容与错误码的功能。

API响应示例：

{"page":2,"per_page":6,"total":12,"total_pages":2,"data":[{"id":7,"email":"michael.lawson@reqres.in","first_name":"Michael","last_name":"Lawson","avatar":"https://reqres.in/img/faces/7-image.jpg"},{"id":8,"email":"lindsay.ferguson@reqres.in","first_name":"Lindsay","last_name":"Ferguson","avatar":"https://reqres.in/img/faces/8-image.jpg"},{"id":9,"email":"tobias.funke@reqres.in","first_name":"Tobias","last_name":"Funke","avatar":"https://reqres.in/img/faces/9-image.jpg"},{"id":10,"email":"byron.fields@reqres.in","first_name":"Byron","last_name":"Fields","avatar":"https://reqres.in/img/faces/10-image.jpg"},{"id":11,"email":"george.edwards@reqres.in","first_name":"George","last_name":"Edwards","avatar":"https://reqres.in/img/faces/11-image.jpg"},{"id":12,"email":"rachel.howell@reqres.in","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!"}}

解决方案 #

1. 修正JSON提取器路径 #

原脚本中JsonExtractor的路径args.data错误，API响应的data字段直接位于根节点，应改为data（或标准JSONPath表达式$.data）。

2. 获取并打印响应与错误码 #

测试运行后，通过stats.samples可获取所有采样结果，遍历每个样本即可提取响应状态码和响应体内容。

修改后的完整脚本 #

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

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

    def test_case_1(self):
        # 修正JSON提取器路径，提取根节点下的data字段
        json_extractor = JsonExtractor("user_data", "data")

        ra = ResponseAssertion().contains_substrings("data")
        http_sampler = HttpSampler("get_users_request", "https://reqres.in/api/users?page=2", ra, json_extractor)

        html_reporter = HtmlReporter()

        # 线程组配置：1线程，1秒启动，持续1秒
        thread_group_main = ThreadGroupWithRampUpAndHold(1, 1, 1, http_sampler)

        test_plan = TestPlan(thread_group_main, html_reporter)

        # 运行测试并获取结果
        stats = test_plan.run()

        # 遍历所有样本，打印响应码和响应体
        for sample in stats.samples:
            print(f"响应状态码: {sample.response_code}")
            print(f"响应内容: {sample.response_body}")
            print("-" * 50)

        self.assertLess(stats.sample_time_99_percentile_milliseconds, 2000)

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

关键说明 #

• stats.samples包含所有采样的详细结果，每个样本对象的response_code属性对应HTTP状态码，response_body属性对应完整的API响应内容。
• 若只需提取响应中的特定字段（如用户列表），已通过JsonExtractor将结果存入user_data变量，可在后续逻辑中直接调用该变量。

内容的提问来源于stack exchange，提问作者Abhishek Kulkarni