python type_error ai_generated true

TypeError: unsupported operand type(s) for -: 'str' and 'float'

ID: python/pytest-approx-comparison-error

Also available as: JSON · Markdown · 中文
80%Fix Rate
85%Confidence
0Evidence
2025-05-10First Seen

Version Compatibility

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

Root Cause

Using pytest.approx() with non-numeric types, such as comparing a string to a float, causing a type error.

generic

中文

使用 pytest.approx() 与非数字类型，例如比较字符串和浮点数，导致类型错误。

Workarounds

  1. 95% success 
    Ensure both operands are numeric: `assert pytest.approx(3.14) == float('3.14')`
  2. 90% success 
    Convert the string to float explicitly: `assert pytest.approx(float('3.14'), 0.01) == 3.14`

Dead Ends

Common approaches that don't work:

  1. 85% fail

    pytest.approx() requires numeric types; string comparison does not support approximate matching.

  2. 70% fail

    This duplicates functionality of approx() and may still fail if types are mismatched.