python type_error ai_generated true

ValueError: The number of names (2) and values (3) must match

ID: python/pytest-parametrize-valueerror

Also available as: JSON · Markdown · 中文
80%Fix Rate
85%Confidence
0Evidence
2024-07-12First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
3.8 active — — —
3.9 active — — —
3.10 active — — —
3.11 active — — —
3.12 active — — —

Root Cause

The @pytest.mark.parametrize decorator has a mismatch between the number of parameter names and the number of values in a tuple.

generic

中文

@pytest.mark.parametrize 装饰器中参数名称的数量与元组中的值的数量不匹配。

Workarounds

  1. 95% success 
    Ensure each tuple in the values list has exactly the same number of elements as names: `@pytest.mark.parametrize('a,b', [(1,2), (3,4)])`
  2. 90% success 
    Use a dictionary for named parameters if the count is variable: `@pytest.mark.parametrize('test_input,expected', [{'test_input': 1, 'expected': 2}])`

Dead Ends

Common approaches that don't work:

  1. 85% fail

    This can lead to confusing test results and unused parameters that obscure the test's purpose.

  2. 70% fail

    This changes the structure of the parameterization, often causing type errors or unexpected test cases.