263 lines
10 KiB
ReStructuredText
263 lines
10 KiB
ReStructuredText
:orphan:
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.. _`pytest helpers`:
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Pytest API and builtin fixtures
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================================================
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Most of the information of this page has been moved over to :ref:`api-reference`.
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For information on plugin hooks and objects, see :ref:`plugins`.
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For information on the ``pytest.mark`` mechanism, see :ref:`mark`.
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For information about fixtures, see :ref:`fixtures`. To see a complete list of available fixtures (add ``-v`` to also see fixtures with leading ``_``), type :
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.. code-block:: pytest
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$ pytest --fixtures -v
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=========================== test session starts ============================
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platform linux -- Python 3.x.y, pytest-8.x.y, pluggy-1.x.y -- $PYTHON_PREFIX/bin/python
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cachedir: .pytest_cache
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rootdir: /home/sweet/project
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collected 0 items
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cache -- .../_pytest/cacheprovider.py:527
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Return a cache object that can persist state between testing sessions.
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cache.get(key, default)
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cache.set(key, value)
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Keys must be ``/`` separated strings, where the first part is usually the
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name of your plugin or application to avoid clashes with other cache users.
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Values can be any object handled by the json stdlib module.
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capsysbinary -- .../_pytest/capture.py:1008
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Enable bytes capturing of writes to ``sys.stdout`` and ``sys.stderr``.
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The captured output is made available via ``capsysbinary.readouterr()``
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method calls, which return a ``(out, err)`` namedtuple.
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``out`` and ``err`` will be ``bytes`` objects.
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Returns an instance of :class:`CaptureFixture[bytes] <pytest.CaptureFixture>`.
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Example:
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.. code-block:: python
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def test_output(capsysbinary):
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print("hello")
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captured = capsysbinary.readouterr()
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assert captured.out == b"hello\n"
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capfd -- .../_pytest/capture.py:1035
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Enable text capturing of writes to file descriptors ``1`` and ``2``.
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The captured output is made available via ``capfd.readouterr()`` method
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calls, which return a ``(out, err)`` namedtuple.
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``out`` and ``err`` will be ``text`` objects.
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Returns an instance of :class:`CaptureFixture[str] <pytest.CaptureFixture>`.
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Example:
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.. code-block:: python
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def test_system_echo(capfd):
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os.system('echo "hello"')
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captured = capfd.readouterr()
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assert captured.out == "hello\n"
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capfdbinary -- .../_pytest/capture.py:1062
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Enable bytes capturing of writes to file descriptors ``1`` and ``2``.
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The captured output is made available via ``capfd.readouterr()`` method
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calls, which return a ``(out, err)`` namedtuple.
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``out`` and ``err`` will be ``byte`` objects.
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Returns an instance of :class:`CaptureFixture[bytes] <pytest.CaptureFixture>`.
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Example:
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.. code-block:: python
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def test_system_echo(capfdbinary):
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os.system('echo "hello"')
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captured = capfdbinary.readouterr()
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assert captured.out == b"hello\n"
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capsys -- .../_pytest/capture.py:981
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Enable text capturing of writes to ``sys.stdout`` and ``sys.stderr``.
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The captured output is made available via ``capsys.readouterr()`` method
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calls, which return a ``(out, err)`` namedtuple.
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``out`` and ``err`` will be ``text`` objects.
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Returns an instance of :class:`CaptureFixture[str] <pytest.CaptureFixture>`.
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Example:
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.. code-block:: python
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def test_output(capsys):
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print("hello")
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captured = capsys.readouterr()
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assert captured.out == "hello\n"
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doctest_namespace [session scope] -- .../_pytest/doctest.py:737
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Fixture that returns a :py:class:`dict` that will be injected into the
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namespace of doctests.
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Usually this fixture is used in conjunction with another ``autouse`` fixture:
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.. code-block:: python
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@pytest.fixture(autouse=True)
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def add_np(doctest_namespace):
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doctest_namespace["np"] = numpy
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For more details: :ref:`doctest_namespace`.
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pytestconfig [session scope] -- .../_pytest/fixtures.py:1346
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Session-scoped fixture that returns the session's :class:`pytest.Config`
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object.
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Example::
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def test_foo(pytestconfig):
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if pytestconfig.getoption("verbose") > 0:
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...
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record_property -- .../_pytest/junitxml.py:283
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Add extra properties to the calling test.
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User properties become part of the test report and are available to the
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configured reporters, like JUnit XML.
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The fixture is callable with ``name, value``. The value is automatically
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XML-encoded.
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Example::
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def test_function(record_property):
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record_property("example_key", 1)
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record_xml_attribute -- .../_pytest/junitxml.py:306
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Add extra xml attributes to the tag for the calling test.
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The fixture is callable with ``name, value``. The value is
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automatically XML-encoded.
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record_testsuite_property [session scope] -- .../_pytest/junitxml.py:344
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Record a new ``<property>`` tag as child of the root ``<testsuite>``.
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This is suitable to writing global information regarding the entire test
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suite, and is compatible with ``xunit2`` JUnit family.
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This is a ``session``-scoped fixture which is called with ``(name, value)``. Example:
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.. code-block:: python
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def test_foo(record_testsuite_property):
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record_testsuite_property("ARCH", "PPC")
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record_testsuite_property("STORAGE_TYPE", "CEPH")
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:param name:
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The property name.
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:param value:
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The property value. Will be converted to a string.
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.. warning::
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Currently this fixture **does not work** with the
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`pytest-xdist <https://github.com/pytest-dev/pytest-xdist>`__ plugin. See
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:issue:`7767` for details.
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tmpdir_factory [session scope] -- .../_pytest/legacypath.py:303
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Return a :class:`pytest.TempdirFactory` instance for the test session.
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tmpdir -- .../_pytest/legacypath.py:310
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Return a temporary directory path object which is unique to each test
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function invocation, created as a sub directory of the base temporary
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directory.
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By default, a new base temporary directory is created each test session,
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and old bases are removed after 3 sessions, to aid in debugging. If
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``--basetemp`` is used then it is cleared each session. See
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:ref:`temporary directory location and retention`.
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The returned object is a `legacy_path`_ object.
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.. note::
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These days, it is preferred to use ``tmp_path``.
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:ref:`About the tmpdir and tmpdir_factory fixtures<tmpdir and tmpdir_factory>`.
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.. _legacy_path: https://py.readthedocs.io/en/latest/path.html
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caplog -- .../_pytest/logging.py:601
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Access and control log capturing.
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Captured logs are available through the following properties/methods::
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* caplog.messages -> list of format-interpolated log messages
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* caplog.text -> string containing formatted log output
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* caplog.records -> list of logging.LogRecord instances
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* caplog.record_tuples -> list of (logger_name, level, message) tuples
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* caplog.clear() -> clear captured records and formatted log output string
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monkeypatch -- .../_pytest/monkeypatch.py:32
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A convenient fixture for monkey-patching.
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The fixture provides these methods to modify objects, dictionaries, or
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:data:`os.environ`:
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* :meth:`monkeypatch.setattr(obj, name, value, raising=True) <pytest.MonkeyPatch.setattr>`
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* :meth:`monkeypatch.delattr(obj, name, raising=True) <pytest.MonkeyPatch.delattr>`
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* :meth:`monkeypatch.setitem(mapping, name, value) <pytest.MonkeyPatch.setitem>`
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* :meth:`monkeypatch.delitem(obj, name, raising=True) <pytest.MonkeyPatch.delitem>`
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* :meth:`monkeypatch.setenv(name, value, prepend=None) <pytest.MonkeyPatch.setenv>`
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* :meth:`monkeypatch.delenv(name, raising=True) <pytest.MonkeyPatch.delenv>`
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* :meth:`monkeypatch.syspath_prepend(path) <pytest.MonkeyPatch.syspath_prepend>`
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* :meth:`monkeypatch.chdir(path) <pytest.MonkeyPatch.chdir>`
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* :meth:`monkeypatch.context() <pytest.MonkeyPatch.context>`
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All modifications will be undone after the requesting test function or
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fixture has finished. The ``raising`` parameter determines if a :class:`KeyError`
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or :class:`AttributeError` will be raised if the set/deletion operation does not have the
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specified target.
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To undo modifications done by the fixture in a contained scope,
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use :meth:`context() <pytest.MonkeyPatch.context>`.
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recwarn -- .../_pytest/recwarn.py:31
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Return a :class:`WarningsRecorder` instance that records all warnings emitted by test functions.
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See https://docs.pytest.org/en/latest/how-to/capture-warnings.html for information
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on warning categories.
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tmp_path_factory [session scope] -- .../_pytest/tmpdir.py:241
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Return a :class:`pytest.TempPathFactory` instance for the test session.
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tmp_path -- .../_pytest/tmpdir.py:256
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Return a temporary directory path object which is unique to each test
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function invocation, created as a sub directory of the base temporary
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directory.
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By default, a new base temporary directory is created each test session,
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and old bases are removed after 3 sessions, to aid in debugging.
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This behavior can be configured with :confval:`tmp_path_retention_count` and
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:confval:`tmp_path_retention_policy`.
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If ``--basetemp`` is used then it is cleared each session. See
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:ref:`temporary directory location and retention`.
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The returned object is a :class:`pathlib.Path` object.
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========================== no tests ran in 0.12s ===========================
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You can also interactively ask for help, e.g. by typing on the Python interactive prompt something like:
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.. code-block:: python
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import pytest
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help(pytest)
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