python data_error ai_generated true

AssertionError: assert 'hello' in ''

ID: python/pytest-capsys-output-not-captured

Also available as: JSON · Markdown · 中文
80%Fix Rate
81%Confidence
0Evidence
2025-03-05First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
3.6 active — — —

Root Cause

capsys fixture未正确捕获stdout，通常因为输出被缓冲或使用了错误的捕获模式。

generic

中文

capsys未捕获输出，可能因为缓冲区或捕获模式问题。

Workarounds

  1. 95% success 
    def test_output(capsys):
    print('hello')
    captured = capsys.readouterr()
    assert 'hello' in captured.out
  2. 90% success 
    def test_output(capfd):
    print('hello')
    captured = capfd.readouterr()
    assert 'hello' in captured.out

Dead Ends

Common approaches that don't work:

  1. 80% fail

    print输出可能被capsys捕获，但断言失败说明捕获内容为空。

  2. 90% fail

    与print类似，可能仍被捕获。