pytest可以捕获doctest的输出吗？

Question

我在--doctest-modules上运行pytest，没有其他选择。

我有一个失败的doctest测试，我试图通过向底层代码添加print()语句来调试这个问题。

对于我的常规(非doctest)测试，捕获输出的工作和显示与预期一样，但是doctest测试没有在我的pytest输出中显示stdout，尽管我已经在其中执行了print()语句。

我可以将我的doctest重写为一个非doctest测试，以便让这些print()语句流转，但这听起来像是一件非常曲折的事情。

有没有办法告诉pytest，我也想让它捕获doctests的输出？

$ python --version
Python 3.7.2
$ pytest --version
This is pytest version 3.10.1, imported from /home/gene/.pythonz/pythons/CPython-3.7.2/lib/python3.7/site-packages/pytest.py
setuptools registered plugins:
  pytest-xdist-1.26.1 at /home/gene/.pythonz/pythons/CPython-3.7.2/lib/python3.7/site-packages/xdist/plugin.py
  pytest-xdist-1.26.1 at /home/gene/.pythonz/pythons/CPython-3.7.2/lib/python3.7/site-packages/xdist/looponfail.py
  pytest-pythonpath-0.7.3 at /home/gene/.pythonz/pythons/CPython-3.7.2/lib/python3.7/site-packages/pytest_pythonpath.py
  pytest-mock-1.10.0 at /home/gene/.pythonz/pythons/CPython-3.7.2/lib/python3.7/site-packages/pytest_mock.py
  pytest-forked-1.0.1 at /home/gene/.pythonz/pythons/CPython-3.7.2/lib/python3.7/site-packages/pytest_forked/__init__.py
  hypothesis-4.4.1 at /home/gene/.pythonz/pythons/CPython-3.7.2/lib/python3.7/site-packages/hypothesis/extra/pytestplugin.py
  flaky-3.5.3 at /home/gene/.pythonz/pythons/CPython-3.7.2/lib/python3.7/site-packages/flaky/flaky_pytest_plugin.py

Answer 1

将我的评论转化为答案:最简单的方法是打印到stderr，因为doctest只捕获stdout进行比较。示例：

import sys


def greet(who):
    """Greet someone.

    >>> greet('world')
    'Hello world'

    >>> greet('fizz')
    'Hello fizz'

    >>> greet('buzz')
    'Hello buzz'
    """

    print('input:', who, file=sys.stderr)
    return f'Hello {who}'

运行测试：

$ pytest --doctest-modules -sv
======================================= test session starts ========================================
...
collected 1 item                                                                                   

spam.py::spam.greet input: world
input: fizz
input: buzz
PASSED

===================================== 1 passed in 0.03 seconds =====================================