Pytest API 和内置 fixtures¶
此页面的大部分信息已移至 API 参考。
有关插件钩子和对象的信息，请参阅 编写插件。
有关 pytest.mark 机制的信息，请参阅 如何使用属性标记测试函数。
有关 fixtures 的信息，请参阅 Fixtures 参考。要查看可用 fixtures 的完整列表（添加 -v 也可以查看带有前导 _ 的 fixtures），请输入
$ pytest --fixtures -v
=========================== test session starts ============================
platform linux -- Python 3.x.y, pytest-8.x.y, pluggy-1.x.y -- $PYTHON_PREFIX/bin/python
cachedir: .pytest_cache
rootdir: /home/sweet/project
collected 0 items
cache -- .../_pytest/cacheprovider.py:556
Return a cache object that can persist state between testing sessions.
cache.get(key, default)
cache.set(key, value)
Keys must be ``/`` separated strings, where the first part is usually the
name of your plugin or application to avoid clashes with other cache users.
Values can be any object handled by the json stdlib module.
capsysbinary -- .../_pytest/capture.py:1024
Enable bytes capturing of writes to ``sys.stdout`` and ``sys.stderr``.
The captured output is made available via ``capsysbinary.readouterr()``
method calls, which return a ``(out, err)`` namedtuple.
``out`` and ``err`` will be ``bytes`` objects.
Returns an instance of :class:`CaptureFixture[bytes] <pytest.CaptureFixture>`.
Example:
.. code-block:: python
def test_output(capsysbinary):
print("hello")
captured = capsysbinary.readouterr()
assert captured.out == b"hello\n"
capfd -- .../_pytest/capture.py:1052
Enable text capturing of writes to file descriptors ``1`` and ``2``.
The captured output is made available via ``capfd.readouterr()`` method
calls, which return a ``(out, err)`` namedtuple.
``out`` and ``err`` will be ``text`` objects.
Returns an instance of :class:`CaptureFixture[str] <pytest.CaptureFixture>`.
Example:
.. code-block:: python
def test_system_echo(capfd):
os.system('echo "hello"')
captured = capfd.readouterr()
assert captured.out == "hello\n"
capfdbinary -- .../_pytest/capture.py:1080
Enable bytes capturing of writes to file descriptors ``1`` and ``2``.
The captured output is made available via ``capfd.readouterr()`` method
calls, which return a ``(out, err)`` namedtuple.
``out`` and ``err`` will be ``byte`` objects.
Returns an instance of :class:`CaptureFixture[bytes] <pytest.CaptureFixture>`.
Example:
.. code-block:: python
def test_system_echo(capfdbinary):
os.system('echo "hello"')
captured = capfdbinary.readouterr()
assert captured.out == b"hello\n"
capsys -- .../_pytest/capture.py:996
Enable text capturing of writes to ``sys.stdout`` and ``sys.stderr``.
The captured output is made available via ``capsys.readouterr()`` method
calls, which return a ``(out, err)`` namedtuple.
``out`` and ``err`` will be ``text`` objects.
Returns an instance of :class:`CaptureFixture[str] <pytest.CaptureFixture>`.
Example:
.. code-block:: python
def test_output(capsys):
print("hello")
captured = capsys.readouterr()
assert captured.out == "hello\n"
doctest_namespace [session scope] -- .../_pytest/doctest.py:741
Fixture that returns a :py:class:`dict` that will be injected into the
namespace of doctests.
Usually this fixture is used in conjunction with another ``autouse`` fixture:
.. code-block:: python
@pytest.fixture(autouse=True)
def add_np(doctest_namespace):
doctest_namespace["np"] = numpy
For more details: :ref:`doctest_namespace`.
pytestconfig [session scope] -- .../_pytest/fixtures.py:1345
Session-scoped fixture that returns the session's :class:`pytest.Config`
object.
Example::
def test_foo(pytestconfig):
if pytestconfig.get_verbosity() > 0:
...
record_property -- .../_pytest/junitxml.py:280
Add extra properties to the calling test.
User properties become part of the test report and are available to the
configured reporters, like JUnit XML.
The fixture is callable with ``name, value``. The value is automatically
XML-encoded.
Example::
def test_function(record_property):
record_property("example_key", 1)
record_xml_attribute -- .../_pytest/junitxml.py:303
Add extra xml attributes to the tag for the calling test.
The fixture is callable with ``name, value``. The value is
automatically XML-encoded.
record_testsuite_property [session scope] -- .../_pytest/junitxml.py:341
Record a new ``<property>`` tag as child of the root ``<testsuite>``.
This is suitable to writing global information regarding the entire test
suite, and is compatible with ``xunit2`` JUnit family.
This is a ``session``-scoped fixture which is called with ``(name, value)``. Example:
.. code-block:: python
def test_foo(record_testsuite_property):
record_testsuite_property("ARCH", "PPC")
record_testsuite_property("STORAGE_TYPE", "CEPH")
:param name:
The property name.
:param value:
The property value. Will be converted to a string.
.. warning::
Currently this fixture **does not work** with the
`pytest-xdist <https://github.com/pytest-dev/pytest-xdist>`__ plugin. See
:issue:`7767` for details.
tmpdir_factory [session scope] -- .../_pytest/legacypath.py:298
Return a :class:`pytest.TempdirFactory` instance for the test session.
tmpdir -- .../_pytest/legacypath.py:305
Return a temporary directory (as `legacy_path`_ object)
which is unique to each test function invocation.
The temporary directory is created as a subdirectory
of the base temporary directory, with configurable retention,
as discussed in :ref:`temporary directory location and retention`.
.. note::
These days, it is preferred to use ``tmp_path``.
:ref:`About the tmpdir and tmpdir_factory fixtures<tmpdir and tmpdir_factory>`.
.. _legacy_path: https://py.readthedocs.io/en/latest/path.html
caplog -- .../_pytest/logging.py:598
Access and control log capturing.
Captured logs are available through the following properties/methods::
* caplog.messages -> list of format-interpolated log messages
* caplog.text -> string containing formatted log output
* caplog.records -> list of logging.LogRecord instances
* caplog.record_tuples -> list of (logger_name, level, message) tuples
* caplog.clear() -> clear captured records and formatted log output string
monkeypatch -- .../_pytest/monkeypatch.py:31
A convenient fixture for monkey-patching.
The fixture provides these methods to modify objects, dictionaries, or
:data:`os.environ`:
* :meth:`monkeypatch.setattr(obj, name, value, raising=True) <pytest.MonkeyPatch.setattr>`
* :meth:`monkeypatch.delattr(obj, name, raising=True) <pytest.MonkeyPatch.delattr>`
* :meth:`monkeypatch.setitem(mapping, name, value) <pytest.MonkeyPatch.setitem>`
* :meth:`monkeypatch.delitem(obj, name, raising=True) <pytest.MonkeyPatch.delitem>`
* :meth:`monkeypatch.setenv(name, value, prepend=None) <pytest.MonkeyPatch.setenv>`
* :meth:`monkeypatch.delenv(name, raising=True) <pytest.MonkeyPatch.delenv>`
* :meth:`monkeypatch.syspath_prepend(path) <pytest.MonkeyPatch.syspath_prepend>`
* :meth:`monkeypatch.chdir(path) <pytest.MonkeyPatch.chdir>`
* :meth:`monkeypatch.context() <pytest.MonkeyPatch.context>`
All modifications will be undone after the requesting test function or
fixture has finished. The ``raising`` parameter determines if a :class:`KeyError`
or :class:`AttributeError` will be raised if the set/deletion operation does not have the
specified target.
To undo modifications done by the fixture in a contained scope,
use :meth:`context() <pytest.MonkeyPatch.context>`.
recwarn -- .../_pytest/recwarn.py:35
Return a :class:`WarningsRecorder` instance that records all warnings emitted by test functions.
See :ref:`warnings` for information on warning categories.
tmp_path_factory [session scope] -- .../_pytest/tmpdir.py:241
Return a :class:`pytest.TempPathFactory` instance for the test session.
tmp_path -- .../_pytest/tmpdir.py:256
Return a temporary directory (as :class:`pathlib.Path` object)
which is unique to each test function invocation.
The temporary directory is created as a subdirectory
of the base temporary directory, with configurable retention,
as discussed in :ref:`temporary directory location and retention`.
========================== no tests ran in 0.12s ===========================
您还可以交互式地寻求帮助，例如在 Python 交互式提示符下输入类似这样的内容
import pytest
help(pytest)