python - 如何自动更改为所有doctests的pytest临时目录

Question

我想在每个 doctest 的开头更改为 pytest 临时目录，我想知道是否有一种方法可以自动执行此操作而无需使用以下命令启动每个 doctest:

>>> tmp = getfixture('tmpdir')                                                                                            
>>> old = tmp.chdir()                                                                                                   

Answer 1

一切皆有可能

conftest.py:

import pytest

@pytest.fixture(autouse=True)
def _docdir(request):

    # Trigger ONLY for the doctests.
    doctest_plugin = request.config.pluginmanager.getplugin("doctest")
    if isinstance(request.node, doctest_plugin.DoctestItem):

        # Get the fixture dynamically by its name.
        tmpdir = request.getfuncargvalue('tmpdir')

        # Chdir only for the duration of the test.
        with tmpdir.as_cwd():
            yield

    else:
        # For normal tests, we have to yield, since this is a yield-fixture.
        yield

test_me.py:

import os.path

# Regular tests are NOT chdir'ed.
def test_me():
    moddir = os.path.dirname(__file__)
    assert os.getcwd() == moddir

import_me.py:

import os, os.path

# Doctests are chdir'ed.
def some_func():
    """
    >>> 2+3
    5
    >>> os.getcwd().startswith('/private/')
    True
    """
    pass

希望这能让您了解如何检测 doctest，以及如何在测试期间临时 chdir。

---

此外，您还可以打个断点，查看fixture中request.node.dtest的内容。这样，您可以向文档字符串或 doctest 行添加可选的注释/标记，并相应地进行操作:

(Pdb++) pp request.node.dtest.docstring
"\n    >>> 2+3\n    5\n    >>> os.getcwd().startswith('/private/')\n    True\n    "

(Pdb++) pp request.node.dtest.examples[0].source
'2+3\n'
(Pdb++) pp request.node.dtest.examples[0].want
'5\n'

(Pdb++) pp request.node.dtest.examples[1].source
"os.getcwd().startswith('/private/')\n"
(Pdb++) pp request.node.dtest.examples[1].want
'True\n'
(Pdb++) pp request.node.dtest.examples[1].exc_msg
None