python data_error ai_generated true

Skipped: got empty parameter set for (u)<function test_parse at 0x7f...>

ID: python/pytest-parametrize-empty

Also available as: JSON · Markdown · 中文
80%Fix Rate
83%Confidence
0Evidence
2024-08-19First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
7.x active — — —
8.x active — — —

Root Cause

A `@pytest.mark.parametrize` decorator was given an empty list, so pytest skips the test. Often caused by a fixture or generator returning an empty collection.

generic

中文

`@pytest.mark.parametrize` 装饰器接收到空列表，pytest 因此跳过该测试。常见原因是 fixture 或生成器返回空集合。

Workarounds

  1. 90% success 
    Ensure the parametrize list is non-empty:
CASES = load_cases()
assert CASES, 'no cases loaded'
@pytest.mark.parametrize('u', CASES)
def test_parse(u): ...
  2. 85% success 
    Use `pytest_generate_tests` to dynamically parametrize with a guard:
def pytest_generate_tests(metafunc):
    if 'u' in metafunc.fixturenames:
        cases = load_cases() or [pytest.param(None, marks=pytest.mark.skip('no cases'))]
        metafunc.parametrize('u', cases)

Dead Ends

Common approaches that don't work:

  1. 75% fail

    IDs don't create test cases; the parameter list is still empty.

  2. 65% fail

    Makes the test always skipped, losing coverage silently.