python module_error ai_generated true

ERROR collecting tests/test_app.py ImportError: attempted relative import with no known parent package

ID: python/pytest-collection-import-mismatch

Also available as: JSON · Markdown · 中文
80%Fix Rate
88%Confidence
0Evidence
2024-05-19First Seen

Version Compatibility

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

Root Cause

Pytest uses rootdir-based import modes. If `tests/` lacks an `__init__.py` and the test uses a relative import like `from .helpers import x`, Python cannot resolve the parent package.

generic

中文

pytest 使用基于 rootdir 的导入模式。如果 `tests/` 目录缺少 `__init__.py`，而测试中使用了 `from .helpers import x` 这类相对导入，Python 就无法解析父包。

Workarounds

  1. 90% success 
    Add an empty `__init__.py` to the tests directory so it becomes a package:

touch tests/__init__.py
  2. 90% success 
    Switch to absolute imports and set rootdir on sys.path via pyproject:

# pyproject.toml
[tool.pytest.ini_options]
pythonpath = ["."]

# test file
from tests.helpers import make_client

Dead Ends

Common approaches that don't work:

  1. 85% fail

    Relative imports are resolved by Python's import machinery, not sys.path; adding the path does not create a parent package.

  2. 70% fail

    Changes rootdir and breaks other tests; the relative import still fails because there is still no package.