python module_error ai_generated true

ImportError: cannot import name 'helpers' from partially initialized module 'tests' (most likely due to a circular import)

ID: python/pytest-conftest-import-shadowing

Also available as: JSON · Markdown · 中文
80%Fix Rate
82%Confidence
0Evidence
2025-04-02First Seen

Version Compatibility

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

Root Cause

Two conftest.py files in nested test directories import the same helper module that itself imports from the test package, creating a cycle during pytest collection.

generic

中文

嵌套测试目录中的两个 conftest.py 导入同一个 helper 模块，而该模块又从测试包导入，导致 pytest 收集期间形成循环。

Workarounds

  1. 90% success 
    # Layout:
# tests/conftest.py
# tests/helpers.py  <-- imports tests.something (cycle)
# Fix: move helpers to project root
# helpers.py
import sys, pathlib
sys.path.insert(0, str(pathlib.Path(__file__).parent))
import helpers
  2. 88% success 
    # tests/conftest.py
@pytest.fixture
def client():
    from tests.helpers import make_client  # imported at call time
    return make_client()

Dead Ends

Common approaches that don't work:

  1. 70% fail

    Making tests a package can change rootdir behavior and does not break the import cycle between helpers and conftest.

  2. 80% fail

    Deferred import still triggers the cycle if helpers imports from tests at module load time.