# Reference¶

## Functions¶

### pytest.approx¶

`approx`(expected, rel=None, abs=None, nan_ok=False)[source]

Assert that two numbers (or two sets of numbers) are equal to each other within some tolerance.

Due to the intricacies of floating-point arithmetic, numbers that we would intuitively expect to be equal are not always so:

```>>> 0.1 + 0.2 == 0.3
False
```

This problem is commonly encountered when writing tests, e.g. when making sure that floating-point values are what you expect them to be. One way to deal with this problem is to assert that two floating-point numbers are equal to within some appropriate tolerance:

```>>> abs((0.1 + 0.2) - 0.3) < 1e-6
True
```

However, comparisons like this are tedious to write and difficult to understand. Furthermore, absolute comparisons like the one above are usually discouraged because there’s no tolerance that works well for all situations. `1e-6` is good for numbers around `1`, but too small for very big numbers and too big for very small ones. It’s better to express the tolerance as a fraction of the expected value, but relative comparisons like that are even more difficult to write correctly and concisely.

The `approx` class performs floating-point comparisons using a syntax that’s as intuitive as possible:

```>>> from pytest import approx
>>> 0.1 + 0.2 == approx(0.3)
True
```

The same syntax also works for sequences of numbers:

```>>> (0.1 + 0.2, 0.2 + 0.4) == approx((0.3, 0.6))
True
```

Dictionary values:

```>>> {'a': 0.1 + 0.2, 'b': 0.2 + 0.4} == approx({'a': 0.3, 'b': 0.6})
True
```

`numpy` arrays:

```>>> import numpy as np
>>> np.array([0.1, 0.2]) + np.array([0.2, 0.4]) == approx(np.array([0.3, 0.6]))
True
```

And for a `numpy` array against a scalar:

```>>> import numpy as np
>>> np.array([0.1, 0.2]) + np.array([0.2, 0.1]) == approx(0.3)
True
```

By default, `approx` considers numbers within a relative tolerance of `1e-6` (i.e. one part in a million) of its expected value to be equal. This treatment would lead to surprising results if the expected value was `0.0`, because nothing but `0.0` itself is relatively close to `0.0`. To handle this case less surprisingly, `approx` also considers numbers within an absolute tolerance of `1e-12` of its expected value to be equal. Infinity and NaN are special cases. Infinity is only considered equal to itself, regardless of the relative tolerance. NaN is not considered equal to anything by default, but you can make it be equal to itself by setting the `nan_ok` argument to True. (This is meant to facilitate comparing arrays that use NaN to mean “no data”.)

Both the relative and absolute tolerances can be changed by passing arguments to the `approx` constructor:

```>>> 1.0001 == approx(1)
False
>>> 1.0001 == approx(1, rel=1e-3)
True
>>> 1.0001 == approx(1, abs=1e-3)
True
```

If you specify `abs` but not `rel`, the comparison will not consider the relative tolerance at all. In other words, two numbers that are within the default relative tolerance of `1e-6` will still be considered unequal if they exceed the specified absolute tolerance. If you specify both `abs` and `rel`, the numbers will be considered equal if either tolerance is met:

```>>> 1 + 1e-8 == approx(1)
True
>>> 1 + 1e-8 == approx(1, abs=1e-12)
False
>>> 1 + 1e-8 == approx(1, rel=1e-6, abs=1e-12)
True
```

If you’re thinking about using `approx`, then you might want to know how it compares to other good ways of comparing floating-point numbers. All of these algorithms are based on relative and absolute tolerances and should agree for the most part, but they do have meaningful differences:

• `math.isclose(a, b, rel_tol=1e-9, abs_tol=0.0)`: True if the relative tolerance is met w.r.t. either `a` or `b` or if the absolute tolerance is met. Because the relative tolerance is calculated w.r.t. both `a` and `b`, this test is symmetric (i.e. neither `a` nor `b` is a “reference value”). You have to specify an absolute tolerance if you want to compare to `0.0` because there is no tolerance by default. Only available in python>=3.5. More information...
• `numpy.isclose(a, b, rtol=1e-5, atol=1e-8)`: True if the difference between `a` and `b` is less that the sum of the relative tolerance w.r.t. `b` and the absolute tolerance. Because the relative tolerance is only calculated w.r.t. `b`, this test is asymmetric and you can think of `b` as the reference value. Support for comparing sequences is provided by `numpy.allclose`. More information...
• `unittest.TestCase.assertAlmostEqual(a, b)`: True if `a` and `b` are within an absolute tolerance of `1e-7`. No relative tolerance is considered and the absolute tolerance cannot be changed, so this function is not appropriate for very large or very small numbers. Also, it’s only available in subclasses of `unittest.TestCase` and it’s ugly because it doesn’t follow PEP8. More information...
• `a == pytest.approx(b, rel=1e-6, abs=1e-12)`: True if the relative tolerance is met w.r.t. `b` or if the absolute tolerance is met. Because the relative tolerance is only calculated w.r.t. `b`, this test is asymmetric and you can think of `b` as the reference value. In the special case that you explicitly specify an absolute tolerance but not a relative tolerance, only the absolute tolerance is considered.

Warning

Changed in version 3.2.

In order to avoid inconsistent behavior, `TypeError` is raised for `>`, `>=`, `<` and `<=` comparisons. The example below illustrates the problem:

```assert approx(0.1) > 0.1 + 1e-10  # calls approx(0.1).__gt__(0.1 + 1e-10)
assert 0.1 + 1e-10 > approx(0.1)  # calls approx(0.1).__lt__(0.1 + 1e-10)
```

In the second example one expects `approx(0.1).__le__(0.1 + 1e-10)` to be called. But instead, `approx(0.1).__lt__(0.1 + 1e-10)` is used to comparison. This is because the call hierarchy of rich comparisons follows a fixed behavior. More information...

### pytest.fail¶

`fail`(msg='', pytrace=True)[source]

explicitly fail an currently-executing test with the given Message.

Parameters: pytrace – if false the msg represents the full failure information and no python traceback will be reported.

### pytest.skip¶

`skip`(msg[, allow_module_level=False])[source]

skip an executing test with the given message. Note: it’s usually better to use the pytest.mark.skipif marker to declare a test to be skipped under certain conditions like mismatching platforms or dependencies. See the pytest_skipping plugin for details.

Parameters: allow_module_level (bool) – allows this function to be called at module level, skipping the rest of the module. Default to False.

### pytest.importorskip¶

`importorskip`(modname, minversion=None)[source]

return imported module if it has at least “minversion” as its __version__ attribute. If no minversion is specified the a skip is only triggered if the module can not be imported.

### pytest.xfail¶

`xfail`(reason='')[source]

xfail an executing test or setup functions with the given reason.

### pytest.exit¶

`exit`(msg)[source]

exit testing process as if KeyboardInterrupt was triggered.

### pytest.main¶

`main`(args=None, plugins=None)[source]

return exit code, after performing an in-process test run.

Parameters: args – list of command line arguments. plugins – list of plugin objects to be auto-registered during initialization.

### pytest.param¶

`param`(*values[, id][, marks])[source]

Specify a parameter in pytest.mark.parametrize calls or parametrized fixtures.

```@pytest.mark.parametrize("test_input,expected", [
("3+5", 8),
pytest.param("6*9", 42, marks=pytest.mark.xfail),
])
def test_eval(test_input, expected):
assert eval(test_input) == expected
```
Parameters: values – variable args of the values of the parameter set, in order. marks – a single mark or a list of marks to be applied to this parameter set. id (str) – the id to attribute to this parameter set.

### pytest.raises¶

with `raises`(expected_exception: Exception[, match][, message]) as excinfo[source]

Assert that a code block/function call raises `expected_exception` and raise a failure exception otherwise.

Parameters: message – if specified, provides a custom failure message if the exception is not raised match – if specified, asserts that the exception matches a text or regex

This helper produces a `ExceptionInfo()` object (see below).

You may use this function as a context manager:

```>>> with raises(ZeroDivisionError):
...    1/0
```

Changed in version 2.10.

In the context manager form you may use the keyword argument `message` to specify a custom failure message:

```>>> with raises(ZeroDivisionError, message="Expecting ZeroDivisionError"):
...    pass
Traceback (most recent call last):
...
Failed: Expecting ZeroDivisionError
```

Note

When using `pytest.raises` as a context manager, it’s worthwhile to note that normal context manager rules apply and that the exception raised must be the final line in the scope of the context manager. Lines of code after that, within the scope of the context manager will not be executed. For example:

```>>> value = 15
>>> with raises(ValueError) as exc_info:
...     if value > 10:
...         raise ValueError("value must be <= 10")
...     assert exc_info.type == ValueError  # this will not execute
```

Instead, the following approach must be taken (note the difference in scope):

```>>> with raises(ValueError) as exc_info:
...     if value > 10:
...         raise ValueError("value must be <= 10")
...
>>> assert exc_info.type == ValueError
```

Since version `3.1` you can use the keyword argument `match` to assert that the exception matches a text or regex:

```>>> with raises(ValueError, match='must be 0 or None'):
...     raise ValueError("value must be 0 or None")

>>> with raises(ValueError, match=r'must be \d+\$'):
...     raise ValueError("value must be 42")
```

Legacy forms

The forms below are fully supported but are discouraged for new code because the context manager form is regarded as more readable and less error-prone.

It is possible to specify a callable by passing a to-be-called lambda:

```>>> raises(ZeroDivisionError, lambda: 1/0)
<ExceptionInfo ...>
```

or you can specify an arbitrary callable with arguments:

```>>> def f(x): return 1/x
...
>>> raises(ZeroDivisionError, f, 0)
<ExceptionInfo ...>
>>> raises(ZeroDivisionError, f, x=0)
<ExceptionInfo ...>
```

It is also possible to pass a string to be evaluated at runtime:

```>>> raises(ZeroDivisionError, "f(0)")
<ExceptionInfo ...>
```

The string will be evaluated using the same `locals()` and `globals()` at the moment of the `raises` call.

Consult the API of `excinfo` objects: `ExceptionInfo`.

Note

Similar to caught exception objects in Python, explicitly clearing local references to returned `ExceptionInfo` objects can help the Python interpreter speed up its garbage collection.

Clearing those references breaks a reference cycle (`ExceptionInfo` –> caught exception –> frame stack raising the exception –> current frame stack –> local variables –> `ExceptionInfo`) which makes Python keep all objects referenced from that cycle (including all local variables in the current frame) alive until the next cyclic garbage collection run. See the official Python `try` statement documentation for more detailed information.

### pytest.deprecated_call¶

with `deprecated_call`()[source]

context manager that can be used to ensure a block of code triggers a `DeprecationWarning` or `PendingDeprecationWarning`:

```>>> import warnings
>>> def api_call_v2():
...     warnings.warn('use v3 of this api', DeprecationWarning)
...     return 200

>>> with deprecated_call():
...    assert api_call_v2() == 200
```

`deprecated_call` can also be used by passing a function and `*args` and `*kwargs`, in which case it will ensure calling `func(*args, **kwargs)` produces one of the warnings types above.

### pytest.register_assert_rewrite¶

Tutorial: Assertion Rewriting.

`register_assert_rewrite`(*names)[source]

Register one or more module names to be rewritten on import.

This function will make sure that this module or all modules inside the package will get their assert statements rewritten. Thus you should make sure to call this before the module is actually imported, usually in your __init__.py if you are a plugin using a package.

Raises: TypeError – if the given module names are not strings.

### pytest.warns¶

with `warns`(expected_warning: Exception[, match])[source]

Assert that code raises a particular class of warning.

Specifically, the parameter `expected_warning` can be a warning class or sequence of warning classes, and the inside the `with` block must issue a warning of that class or classes.

This helper produces a list of `warnings.WarningMessage` objects, one for each warning raised.

This function can be used as a context manager, or any of the other ways `pytest.raises` can be used:

```>>> with warns(RuntimeWarning):
...    warnings.warn("my warning", RuntimeWarning)
```

In the context manager form you may use the keyword argument `match` to assert that the exception matches a text or regex:

```>>> with warns(UserWarning, match='must be 0 or None'):
...     warnings.warn("value must be 0 or None", UserWarning)

>>> with warns(UserWarning, match=r'must be \d+\$'):
...     warnings.warn("value must be 42", UserWarning)

>>> with warns(UserWarning, match=r'must be \d+\$'):
...     warnings.warn("this is not here", UserWarning)
Traceback (most recent call last):
...
Failed: DID NOT WARN. No warnings of type ...UserWarning... was emitted...
```

## Marks¶

Marks can be used apply meta data to test functions (but not fixtures), which can then be accessed by fixtures or plugins.

### pytest.mark.filterwarnings¶

Tutorial: @pytest.mark.filterwarnings.

Add warning filters to marked test items.

`pytest.mark.``filterwarnings`(filter)
Parameters: filter (str) – A warning specification string, which is composed of contents of the tuple `(action, message, category, module, lineno)` as specified in The Warnings filter section of the Python documentation, separated by `":"`. Optional fields can be omitted. For example: ```@pytest.mark.warnings("ignore:.*usage will be deprecated.*:DeprecationWarning") def test_foo(): ... ```

### pytest.mark.parametrize¶

`Metafunc.``parametrize`(argnames, argvalues, indirect=False, ids=None, scope=None)[source]

Add new invocations to the underlying test function using the list of argvalues for the given argnames. Parametrization is performed during the collection phase. If you need to setup expensive resources see about setting indirect to do it rather at test setup time.

Parameters: argnames – a comma-separated string denoting one or more argument names, or a list/tuple of argument strings. argvalues – The list of argvalues determines how often a test is invoked with different argument values. If only one argname was specified argvalues is a list of values. If N argnames were specified, argvalues must be a list of N-tuples, where each tuple-element specifies a value for its respective argname. indirect – The list of argnames or boolean. A list of arguments’ names (subset of argnames). If True the list contains all names from the argnames. Each argvalue corresponding to an argname in this list will be passed as request.param to its respective argname fixture function so that it can perform more expensive setups during the setup phase of a test rather than at collection time. ids – list of string ids, or a callable. If strings, each is corresponding to the argvalues so that they are part of the test id. If None is given as id of specific test, the automatically generated id for that argument will be used. If callable, it should take one argument (a single argvalue) and return a string or return None. If None, the automatically generated id for that argument will be used. If no ids are provided they will be generated automatically from the argvalues. scope – if specified it denotes the scope of the parameters. The scope is used for grouping tests by parameter instances. It will also override any fixture-function defined scope, allowing to set a dynamic scope using test context or configuration.

### pytest.mark.skip¶

Tutorial: Skipping test functions.

Unconditionally skip a test function.

`pytest.mark.``skip`(*, reason=None)
Parameters: reason (str) – Reason why the test function is being skipped.

### pytest.mark.skipif¶

Skip a test function if a condition is `True`.

`pytest.mark.``skipif`(condition, *, reason=None)
Parameters: condition (bool or str) – `True/False` if the condition should be skipped or a condition string. reason (str) – Reason why the test function is being skipped.

### pytest.mark.xfail¶

Marks a test function as expected to fail.

`pytest.mark.``xfail`(condition=None, *, reason=None, raises=None, run=True, strict=False)
Parameters: condition (bool or str) – `True/False` if the condition should be marked as xfail or a condition string. reason (str) – Reason why the test function is marked as xfail. raises (Exception) – Exception subclass expected to be raised by the test function; other exceptions will fail the test. run (bool) – If the test function should actually be executed. If `False`, the function will always xfail and will not be executed (useful a function is segfaulting). strict (bool) – If `False` (the default) the function will be shown in the terminal output as `xfailed` if it fails and as `xpass` if it passes. In both cases this will not cause the test suite to fail as a whole. This is particularly useful to mark flaky tests (tests that random at fail) to be tackled later. If `True`, the function will be shown in the terminal output as `xfailed` if it fails, but if it unexpectedly passes then it will fail the test suite. This is particularly useful to mark functions that are always failing and there should be a clear indication if they unexpectedly start to pass (for example a new release of a library fixes a known bug).

### custom marks¶

Marks are created dynamically using the factory object `pytest.mark` and applied as a decorator.

For example:

```@pytest.mark.timeout(10, 'slow', method='thread')
def test_function():
...
```

Will create and attach a `MarkInfo` object to the collected `Item`, which can then be accessed by fixtures or hooks with `Node.get_marker`. The `mark` object will have the following attributes:

```mark.args == (10, 'slow')
```

## Fixtures¶

Fixtures are requested by test functions or other fixtures by declaring them as argument names.

Example of a test requiring a fixture:

```def test_output(capsys):
print('hello')
assert out == 'hello\n'
```

Example of a fixture requiring another fixture:

```@pytest.fixture
def db_session(tmpdir):
fn = tmpdir / 'db.file'
return connect(str(fn))
```

For more details, consult the full fixtures docs.

### @pytest.fixture¶

`@``fixture`(scope='function', params=None, autouse=False, ids=None, name=None)[source]

Decorator to mark a fixture factory function.

This decorator can be used (with or without parameters) to define a fixture function. The name of the fixture function can later be referenced to cause its invocation ahead of running tests: test modules or classes can use the pytest.mark.usefixtures(fixturename) marker. Test functions can directly use fixture names as input arguments in which case the fixture instance returned from the fixture function will be injected.

Parameters: scope – the scope for which this fixture is shared, one of “function” (default), “class”, “module” or “session”. params – an optional list of parameters which will cause multiple invocations of the fixture function and all of the tests using it. autouse – if True, the fixture func is activated for all tests that can see it. If False (the default) then an explicit reference is needed to activate the fixture. ids – list of string ids each corresponding to the params so that they are part of the test id. If no ids are provided they will be generated automatically from the params. name – the name of the fixture. This defaults to the name of the decorated function. If a fixture is used in the same module in which it is defined, the function name of the fixture will be shadowed by the function arg that requests the fixture; one way to resolve this is to name the decorated function `fixture_` and then use `@pytest.fixture(name='')`.

Fixtures can optionally provide their values to test functions using a `yield` statement, instead of `return`. In this case, the code block after the `yield` statement is executed as teardown code regardless of the test outcome. A fixture function must yield exactly once.

### config.cache¶

Tutorial: Cache: working with cross-testrun state.

The `config.cache` object allows other plugins and fixtures to store and retrieve values across test runs. To access it from fixtures request `pytestconfig` into your fixture and get it with `pytestconfig.cache`.

Under the hood, the cache plugin uses the simple `dumps`/`loads` API of the `json` stdlib module.

`Cache.``get`(key, default)[source]

return cached value for the given key. If no value was yet cached or the value cannot be read, the specified default is returned.

Parameters: key – must be a `/` separated value. Usually the first name is the name of your plugin or your application. default – must be provided in case of a cache-miss or invalid cache values.
`Cache.``set`(key, value)[source]

save value for the given key.

Parameters: key – must be a `/` separated value. Usually the first name is the name of your plugin or your application. value – must be of any combination of basic python types, including nested types like e. g. lists of dictionaries.
`Cache.``makedir`(name)[source]

return a directory path object with the given name. If the directory does not yet exist, it will be created. You can use it to manage files likes e. g. store/retrieve database dumps across test sessions.

Parameters: name – must be a string not containing a `/` separator. Make sure the name contains your plugin or application identifiers to prevent clashes with other cache users.

### capsys¶

Tutorial: Capturing of the stdout/stderr output.

`capsys`()[source]

Enable capturing of writes to `sys.stdout` and `sys.stderr` and make captured output available via `capsys.readouterr()` method calls which return a `(out, err)` namedtuple. `out` and `err` will be `text` objects.

Returns an instance of `CaptureFixture`.

Example:

```def test_output(capsys):
print("hello")
assert captured.out == "hello\n"
```
class `CaptureFixture`[source]

Object returned by `capsys()`, `capsysbinary()`, `capfd()` and `capfdbinary()` fixtures.

`readouterr`()[source]

Read and return the captured output so far, resetting the internal buffer.

Returns: captured content as a namedtuple with `out` and `err` string attributes
with `disabled`()[source]

Temporarily disables capture while inside the ‘with’ block.

### capsysbinary¶

Tutorial: Capturing of the stdout/stderr output.

`capsysbinary`()[source]

Enable capturing of writes to `sys.stdout` and `sys.stderr` and make captured output available via `capsys.readouterr()` method calls which return a `(out, err)` tuple. `out` and `err` will be `bytes` objects.

Returns an instance of `CaptureFixture`.

Example:

```def test_output(capsysbinary):
print("hello")
assert captured.out == b"hello\n"
```

### capfd¶

Tutorial: Capturing of the stdout/stderr output.

`capfd`()[source]

Enable capturing of writes to file descriptors `1` and `2` and make captured output available via `capfd.readouterr()` method calls which return a `(out, err)` tuple. `out` and `err` will be `text` objects.

Returns an instance of `CaptureFixture`.

Example:

```def test_system_echo(capfd):
os.system('echo "hello"')
assert captured.out == "hello\n"
```

### capfdbinary¶

Tutorial: Capturing of the stdout/stderr output.

`capfdbinary`()[source]

Enable capturing of write to file descriptors 1 and 2 and make captured output available via `capfdbinary.readouterr` method calls which return a `(out, err)` tuple. `out` and `err` will be `bytes` objects.

Returns an instance of `CaptureFixture`.

Example:

```def test_system_echo(capfdbinary):
os.system('echo "hello"')
assert captured.out == b"hello\n"
```

### doctest_namespace¶

`doctest_namespace`()[source]

Fixture that returns a `dict` that will be injected into the namespace of doctests.

Usually this fixture is used in conjunction with another `autouse` fixture:

```@pytest.fixture(autouse=True)
doctest_namespace['np'] = numpy
```

For more details: The ‘doctest_namespace’ fixture.

### request¶

The `request` fixture is a special fixture providing information of the requesting test function.

class `FixtureRequest`[source]

A request for a fixture from a test or fixture function.

A request object gives access to the requesting test context and has an optional `param` attribute in case the fixture is parametrized indirectly.

`fixturename` = None

fixture for which this request is being performed

`scope` = None

Scope string, one of “function”, “class”, “module”, “session”

`node`

underlying collection node (depends on current request scope)

`config`

the pytest config object associated with this request.

`function`

test function object if the request has a per-function scope.

`cls`

class (can be None) where the test function was collected.

`instance`

instance (can be None) on which test function was collected.

`module`

python module object where the test function was collected.

`fspath`

the file system path of the test module which collected this test.

`keywords`

keywords/markers dictionary for the underlying node.

`session`

pytest session object.

`addfinalizer`(finalizer)[source]

add finalizer/teardown function to be called after the last test within the requesting test context finished execution.

`applymarker`(marker)[source]

Apply a marker to a single test function invocation. This method is useful if you don’t want to have a keyword/marker on all function invocations.

Parameters: marker – a `_pytest.mark.MarkDecorator` object created by a call to `pytest.mark.NAME(...)`.
`raiseerror`(msg)[source]

raise a FixtureLookupError with the given message.

`cached_setup`(setup, teardown=None, scope='module', extrakey=None)[source]

(deprecated) Return a testing resource managed by `setup` & `teardown` calls. `scope` and `extrakey` determine when the `teardown` function will be called so that subsequent calls to `setup` would recreate the resource. With pytest-2.3 you often do not need `cached_setup()` as you can directly declare a scope on a fixture function and register a finalizer through `request.addfinalizer()`.

Parameters: teardown – function receiving a previously setup resource. setup – a no-argument function creating a resource. scope – a string value out of `function`, `class`, `module` or `session` indicating the caching lifecycle of the resource. extrakey – added to internal caching key of (funcargname, scope).
`getfixturevalue`(argname)[source]

Dynamically run a named fixture function.

Declaring fixtures via function argument is recommended where possible. But if you can only decide whether to use another fixture at test setup time, you may use this function to retrieve it inside a fixture or test function body.

`getfuncargvalue`(argname)[source]

Deprecated, use getfixturevalue.

### pytestconfig¶

`pytestconfig`()[source]

Session-scoped fixture that returns the `_pytest.config.Config` object.

Example:

```def test_foo(pytestconfig):
if pytestconfig.getoption("verbose"):
...
```

### record_property¶

Tutorial: record_property.

`record_property`()[source]

Add an extra properties 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)`, with value being automatically xml-encoded.

Example:

```def test_function(record_property):
record_property("example_key", 1)
```

### caplog¶

Tutorial: Logging.

`caplog`()[source]

Access and control log capturing.

Captured logs are available through the following methods:

```* 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
```

This returns a `_pytest.logging.LogCaptureFixture` instance.

class `LogCaptureFixture`(item)[source]

Provides access and control of log capturing.

`handler`
Return type: LogCaptureHandler
`get_records`(when)[source]

Get the logging records for one of the possible test phases.

Parameters: when (str) – Which test phase to obtain the records from. Valid values are: “setup”, “call” and “teardown”. List[logging.LogRecord] the list of captured records at the given stage

New in version 3.4.

`text`

Returns the log text.

`records`

Returns the list of log records.

`record_tuples`

Returns a list of a striped down version of log records intended for use in assertion comparison.

The format of the tuple is:

(logger_name, log_level, message)
`clear`()[source]

Reset the list of log records and the captured log text.

`set_level`(level, logger=None)[source]

Sets the level for capturing of logs. The level will be restored to its previous value at the end of the test.

Parameters: level (int) – the logger to level. logger (str) – the logger to update the level. If not given, the root logger level is updated.

Changed in version 3.4: The levels of the loggers changed by this function will be restored to their initial values at the end of the test.

with `at_level`(level, logger=None)[source]

Context manager that sets the level for capturing of logs. After the end of the ‘with’ statement the level is restored to its original value.

Parameters: level (int) – the logger to level. logger (str) – the logger to update the level. If not given, the root logger level is updated.

### monkeypatch¶

`monkeypatch`()[source]

The returned `monkeypatch` fixture provides these helper methods to modify objects, dictionaries or os.environ:

```monkeypatch.setattr(obj, name, value, raising=True)
monkeypatch.delattr(obj, name, raising=True)
monkeypatch.setitem(mapping, name, value)
monkeypatch.delitem(obj, name, raising=True)
monkeypatch.setenv(name, value, prepend=False)
monkeypatch.delenv(name, value, raising=True)
monkeypatch.syspath_prepend(path)
monkeypatch.chdir(path)
```

All modifications will be undone after the requesting test function or fixture has finished. The `raising` parameter determines if a KeyError or AttributeError will be raised if the set/deletion operation has no target.

This returns a `MonkeyPatch` instance.

class `MonkeyPatch`[source]

Object returned by the `monkeypatch` fixture keeping a record of setattr/item/env/syspath changes.

`setattr`(target, name, value=<notset>, raising=True)[source]

Set attribute value on target, memorizing the old value. By default raise AttributeError if the attribute did not exist.

For convenience you can specify a string as `target` which will be interpreted as a dotted import path, with the last part being the attribute name. Example: `monkeypatch.setattr("os.getcwd", lambda: "/")` would set the `getcwd` function of the `os` module.

The `raising` value determines if the setattr should fail if the attribute is not already present (defaults to True which means it will raise).

`delattr`(target, name=<notset>, raising=True)[source]

Delete attribute `name` from `target`, by default raise AttributeError it the attribute did not previously exist.

If no `name` is specified and `target` is a string it will be interpreted as a dotted import path with the last part being the attribute name.

If `raising` is set to False, no exception will be raised if the attribute is missing.

`setitem`(dic, name, value)[source]

Set dictionary entry `name` to value.

`delitem`(dic, name, raising=True)[source]

Delete `name` from dict. Raise KeyError if it doesn’t exist.

If `raising` is set to False, no exception will be raised if the key is missing.

`setenv`(name, value, prepend=None)[source]

Set environment variable `name` to `value`. If `prepend` is a character, read the current environment variable value and prepend the `value` adjoined with the `prepend` character.

`delenv`(name, raising=True)[source]

Delete `name` from the environment. Raise KeyError it does not exist.

If `raising` is set to False, no exception will be raised if the environment variable is missing.

`syspath_prepend`(path)[source]

Prepend `path` to `sys.path` list of import locations.

`chdir`(path)[source]

Change the current working directory to the specified path. Path can be a string or a py.path.local object.

`undo`()[source]

Undo previous changes. This call consumes the undo stack. Calling it a second time has no effect unless you do more monkeypatching after the undo call.

There is generally no need to call undo(), since it is called automatically during tear-down.

Note that the same monkeypatch fixture is used across a single test function invocation. If monkeypatch is used both by the test function itself and one of the test fixtures, calling undo() will undo all of the changes made in both functions.

### testdir¶

This fixture provides a `Testdir` instance useful for black-box testing of test files, making it ideal to test plugins.

To use it, include in your top-most `conftest.py` file:

```pytest_plugins = 'pytester'
```
class `Testdir`[source]

Temporary test directory with tools to test/run pytest itself.

This is based on the `tmpdir` fixture but provides a number of methods which aid with testing pytest itself. Unless `chdir()` is used all methods will use `tmpdir` as their current working directory.

Attributes:

Tmpdir: The `py.path.local` instance of the temporary directory. A list of plugins to use with `parseconfig()` and `runpytest()`. Initially this is an empty list but plugins can be added to the list. The type of items to add to the list depends on the method using them so refer to them for details.
`makeconftest`(source)[source]

Write a contest.py file with ‘source’ as contents.

`makepyfile`(*args, **kwargs)[source]

Shortcut for .makefile() with a .py extension.

`runpytest_inprocess`(*args, **kwargs)[source]

Return result of running pytest in-process, providing a similar interface to what self.runpytest() provides.

`runpytest`(*args, **kwargs)[source]

Run pytest inline or in a subprocess, depending on the command line option “–runpytest” and return a `RunResult`.

`runpytest_subprocess`(*args, **kwargs)[source]

Run pytest as a subprocess with given arguments.

Any plugins added to the `plugins` list will added using the `-p` command line option. Additionally `--basetemp` is used put any temporary files and directories in a numbered directory prefixed with “runpytest-” so they do not conflict with the normal numbered pytest location for temporary files and directories.

Returns a `RunResult`.

class `RunResult`[source]

The result of running a command.

Attributes:

Ret: the return value list of lines captured from stdout list of lines captures from stderr `LineMatcher` of stdout, use `stdout.str()` to reconstruct stdout or the commonly used `stdout.fnmatch_lines()` method `LineMatcher` of stderr duration in seconds
`parseoutcomes`()[source]

Return a dictionary of outcomestring->num from parsing the terminal output that the test process produced.

`assert_outcomes`(passed=0, skipped=0, failed=0, error=0)[source]

Assert that the specified outcomes appear with the respective numbers (0 means it didn’t occur) in the text output from a test run.

class `LineMatcher`[source]

Flexible matching of text.

This is a convenience class to test large texts like the output of commands.

The constructor takes a list of lines without their trailing newlines, i.e. `text.splitlines()`.

`str`()[source]

Return the entire original text.

`fnmatch_lines_random`(lines2)[source]

Check lines exist in the output using in any order.

Lines are checked using `fnmatch.fnmatch`. The argument is a list of lines which have to occur in the output, in any order.

`re_match_lines_random`(lines2)[source]

Check lines exist in the output using `re.match`, in any order.

The argument is a list of lines which have to occur in the output, in any order.

`get_lines_after`(fnline)[source]

Return all lines following the given line in the text.

The given line can contain glob wildcards.

`fnmatch_lines`(lines2)[source]

Search captured text for matching lines using `fnmatch.fnmatch`.

The argument is a list of lines which have to match and can use glob wildcards. If they do not match a pytest.fail() is called. The matches and non-matches are also printed on stdout.

`re_match_lines`(lines2)[source]

Search captured text for matching lines using `re.match`.

The argument is a list of lines which have to match using `re.match`. If they do not match a pytest.fail() is called.

The matches and non-matches are also printed on stdout.

### recwarn¶

`recwarn`()[source]

Return a `WarningsRecorder` instance that records all warnings emitted by test functions.

See http://docs.python.org/library/warnings.html for information on warning categories.

class `WarningsRecorder`[source]

A context manager to record raised warnings.

`list`

The list of recorded warnings.

`pop`(cls=<class 'Warning'>)[source]

Pop the first recorded warning, raise exception if not exists.

`clear`()[source]

Clear the list of recorded warnings.

Each recorded warning is an instance of `warnings.WarningMessage`.

Note

`RecordedWarning` was changed from a plain class to a namedtuple in pytest 3.1

Note

`DeprecationWarning` and `PendingDeprecationWarning` are treated differently; see Ensuring a function triggers a deprecation warning.

### tmpdir¶

Tutorial: Temporary directories and files

`tmpdir`()[source]

Return a temporary directory path object which is unique to each test function invocation, created as a sub directory of the base temporary directory. The returned object is a py.path.local path object.

### tmpdir_factory¶

Tutorial: The ‘tmpdir_factory’ fixture

`tmpdir_factory` instances have the following methods:

`TempdirFactory.``mktemp`(basename, numbered=True)[source]

Create a subdirectory of the base temporary directory and return it. If `numbered`, ensure the directory is unique by adding a number prefix greater than any existing one.

`TempdirFactory.``getbasetemp`()[source]

return base temporary directory.

## Hooks¶

Tutorial: Writing plugins.

Reference to all hooks which can be implemented by conftest.py files and plugins.

### Bootstrapping hooks¶

Bootstrapping hooks called for plugins registered early enough (internal and setuptools plugins).

`pytest_load_initial_conftests`(early_config, parser, args)[source]

Note

This hook will not be called for `conftest.py` files, only for setuptools plugins.

Parameters: early_config (_pytest.config.Config) – pytest config object args (list[str]) – list of arguments passed on the command line parser (_pytest.config.Parser) – to add command line options
`pytest_cmdline_preparse`(config, args)[source]

(Deprecated) modify command line arguments before option parsing.

This hook is considered deprecated and will be removed in a future pytest version. Consider using `pytest_load_initial_conftests()` instead.

Note

This hook will not be called for `conftest.py` files, only for setuptools plugins.

Parameters: config (_pytest.config.Config) – pytest config object args (list[str]) – list of arguments passed on the command line
`pytest_cmdline_parse`(pluginmanager, args)[source]

return initialized config object, parsing the specified args.

Stops at first non-None result, see firstresult: stop at first non-None result

Note

This hook will not be called for `conftest.py` files, only for setuptools plugins.

Parameters: pluginmanager (_pytest.config.PytestPluginManager) – pytest plugin manager args (list[str]) – list of arguments passed on the command line
`pytest_cmdline_main`(config)[source]

called for performing the main command line action. The default implementation will invoke the configure hooks and runtest_mainloop.

Note

This hook will not be called for `conftest.py` files, only for setuptools plugins.

Stops at first non-None result, see firstresult: stop at first non-None result

Parameters: config (_pytest.config.Config) – pytest config object

### Initialization hooks¶

Initialization hooks called for plugins and `conftest.py` files.

`pytest_addoption`(parser)[source]

register argparse-style options and ini-style config values, called once at the beginning of a test run.

Note

This function should be implemented only in plugins or `conftest.py` files situated at the tests root directory due to how pytest discovers plugins during startup.

Parameters: parser (_pytest.config.Parser) – To add command line options, call `parser.addoption(...)`. To add ini-file values call `parser.addini(...)`.

Options can later be accessed through the `config` object, respectively:

The config object is passed around on many internal objects via the `.config` attribute or can be retrieved as the `pytestconfig` fixture.

Note

This hook is incompatible with `hookwrapper=True`.

`pytest_addhooks`(pluginmanager)[source]

called at plugin registration time to allow adding new hooks via a call to `pluginmanager.add_hookspecs(module_or_class, prefix)`.

Parameters: pluginmanager (_pytest.config.PytestPluginManager) – pytest plugin manager

Note

This hook is incompatible with `hookwrapper=True`.

`pytest_configure`(config)[source]

Allows plugins and conftest files to perform initial configuration.

This hook is called for every plugin and initial conftest file after command line options have been parsed.

After that, the hook is called for other conftest files as they are imported.

Note

This hook is incompatible with `hookwrapper=True`.

Parameters: config (_pytest.config.Config) – pytest config object
`pytest_unconfigure`(config)[source]

called before test process is exited.

Parameters: config (_pytest.config.Config) – pytest config object
`pytest_sessionstart`(session)[source]

called after the `Session` object has been created and before performing collection and entering the run test loop.

Parameters: session (_pytest.main.Session) – the pytest session object
`pytest_sessionfinish`(session, exitstatus)[source]

called after whole test run finished, right before returning the exit status to the system.

Parameters: session (_pytest.main.Session) – the pytest session object exitstatus (int) – the status which pytest will return to the system

### Test running hooks¶

All runtest related hooks receive a `pytest.Item` object.

`pytest_runtestloop`(session)[source]

called for performing the main runtest loop (after collection finished).

Stops at first non-None result, see firstresult: stop at first non-None result

Parameters: session (_pytest.main.Session) – the pytest session object
`pytest_runtest_protocol`(item, nextitem)[source]

implements the runtest_setup/call/teardown protocol for the given test item, including capturing exceptions and calling reporting hooks.

Parameters: item – test item for which the runtest protocol is performed. nextitem – the scheduled-to-be-next test item (or None if this is the end my friend). This argument is passed on to `pytest_runtest_teardown()`. True if no further hook implementations should be invoked.

Stops at first non-None result, see firstresult: stop at first non-None result

`pytest_runtest_logstart`(nodeid, location)[source]

signal the start of running a single test item.

This hook will be called before `pytest_runtest_setup()`, `pytest_runtest_call()` and `pytest_runtest_teardown()` hooks.

Parameters: nodeid (str) – full id of the item location – a triple of `(filename, linenum, testname)`
`pytest_runtest_logfinish`(nodeid, location)[source]

signal the complete finish of running a single test item.

This hook will be called after `pytest_runtest_setup()`, `pytest_runtest_call()` and `pytest_runtest_teardown()` hooks.

Parameters: nodeid (str) – full id of the item location – a triple of `(filename, linenum, testname)`
`pytest_runtest_setup`(item)[source]

called before `pytest_runtest_call(item)`.

`pytest_runtest_call`(item)[source]

called to execute the test `item`.

`pytest_runtest_teardown`(item, nextitem)[source]

called after `pytest_runtest_call`.

Parameters: nextitem – the scheduled-to-be-next test item (None if no further test item is scheduled). This argument can be used to perform exact teardowns, i.e. calling just enough finalizers so that nextitem only needs to call setup-functions.
`pytest_runtest_makereport`(item, call)[source]

return a `_pytest.runner.TestReport` object for the given `pytest.Item` and `_pytest.runner.CallInfo`.

Stops at first non-None result, see firstresult: stop at first non-None result

For deeper understanding you may look at the default implementation of these hooks in `_pytest.runner` and maybe also in `_pytest.pdb` which interacts with `_pytest.capture` and its input/output capturing in order to immediately drop into interactive debugging when a test failure occurs.

The `_pytest.terminal` reported specifically uses the reporting hook to print information about a test run.

### Collection hooks¶

`pytest` calls the following hooks for collecting files and directories:

`pytest_collection`(session)[source]

Perform the collection protocol for the given session.

Stops at first non-None result, see firstresult: stop at first non-None result.

Parameters: session (_pytest.main.Session) – the pytest session object
`pytest_ignore_collect`(path, config)[source]

return True to prevent considering this path for collection. This hook is consulted for all files and directories prior to calling more specific hooks.

Stops at first non-None result, see firstresult: stop at first non-None result

Parameters: path (str) – the path to analyze config (_pytest.config.Config) – pytest config object
`pytest_collect_directory`(path, parent)[source]

called before traversing a directory for collection files.

Stops at first non-None result, see firstresult: stop at first non-None result

Parameters: path (str) – the path to analyze
`pytest_collect_file`(path, parent)[source]

return collection Node or None for the given path. Any new node needs to have the specified `parent` as a parent.

Parameters: path (str) – the path to collect

For influencing the collection of objects in Python modules you can use the following hook:

`pytest_pycollect_makeitem`(collector, name, obj)[source]

return custom item/collector for a python object in a module, or None.

Stops at first non-None result, see firstresult: stop at first non-None result

`pytest_generate_tests`(metafunc)[source]

generate (multiple) parametrized calls to a test function.

`pytest_make_parametrize_id`(config, val, argname)[source]

Return a user-friendly string representation of the given `val` that will be used by @pytest.mark.parametrize calls. Return None if the hook doesn’t know about `val`. The parameter name is available as `argname`, if required.

Stops at first non-None result, see firstresult: stop at first non-None result

Parameters: config (_pytest.config.Config) – pytest config object val – the parametrized value argname (str) – the automatic parameter name produced by pytest

After collection is complete, you can modify the order of items, delete or otherwise amend the test items:

`pytest_collection_modifyitems`(session, config, items)[source]

called after collection has been performed, may filter or re-order the items in-place.

Parameters: session (_pytest.main.Session) – the pytest session object config (_pytest.config.Config) – pytest config object items (List[_pytest.nodes.Item]) – list of item objects

### Reporting hooks¶

Session related reporting hooks:

`pytest_collectstart`(collector)[source]

collector starts collecting.

`pytest_itemcollected`(item)[source]

we just collected a test item.

`pytest_collectreport`(report)[source]

collector finished collecting.

`pytest_deselected`(items)[source]

called for test items deselected by keyword.

`pytest_report_header`(config, startdir)[source]

return a string or list of strings to be displayed as header info for terminal reporting.

Parameters: config (_pytest.config.Config) – pytest config object startdir – py.path object with the starting dir

Note

This function should be implemented only in plugins or `conftest.py` files situated at the tests root directory due to how pytest discovers plugins during startup.

`pytest_report_collectionfinish`(config, startdir, items)[source]

New in version 3.2.

return a string or list of strings to be displayed after collection has finished successfully.

This strings will be displayed after the standard “collected X items” message.

Parameters: config (_pytest.config.Config) – pytest config object startdir – py.path object with the starting dir items – list of pytest items that are going to be executed; this list should not be modified.
`pytest_report_teststatus`(report)[source]

return result-category, shortletter and verbose word for reporting.

Stops at first non-None result, see firstresult: stop at first non-None result

`pytest_terminal_summary`(terminalreporter, exitstatus)[source]

Add a section to terminal summary reporting.

Parameters: terminalreporter (_pytest.terminal.TerminalReporter) – the internal terminal reporter object exitstatus (int) – the exit status that will be reported back to the OS

New in version 3.5: The `config` parameter.

`pytest_fixture_setup`(fixturedef, request)[source]

performs fixture setup execution.

Returns: The return value of the call to the fixture function

Stops at first non-None result, see firstresult: stop at first non-None result

Note

If the fixture function returns None, other implementations of this hook function will continue to be called, according to the behavior of the firstresult: stop at first non-None result option.

`pytest_fixture_post_finalizer`(fixturedef, request)[source]

called after fixture teardown, but before the cache is cleared so the fixture result cache `fixturedef.cached_result` can still be accessed.

And here is the central hook for reporting about test execution:

`pytest_runtest_logreport`(report)[source]

process a test setup/call/teardown report relating to the respective phase of executing a test.

You can also use this hook to customize assertion representation for some types:

`pytest_assertrepr_compare`(config, op, left, right)[source]

return explanation for comparisons in failing assert expressions.

Return None for no custom explanation, otherwise return a list of strings. The strings will be joined by newlines but any newlines in a string will be escaped. Note that all but the first line will be indented slightly, the intention is for the first line to be a summary.

Parameters: config (_pytest.config.Config) – pytest config object

### Debugging/Interaction hooks¶

There are few hooks which can be used for special reporting or interaction with exceptions:

`pytest_internalerror`(excrepr, excinfo)[source]

called for internal errors.

`pytest_keyboard_interrupt`(excinfo)[source]

called for keyboard interrupt.

`pytest_exception_interact`(node, call, report)[source]

called when an exception was raised which can potentially be interactively handled.

This hook is only called if an exception was raised that is not an internal exception like `skip.Exception`.

`pytest_enter_pdb`(config)[source]

called upon pdb.set_trace(), can be used by plugins to take special action just before the python debugger enters in interactive mode.

Parameters: config (_pytest.config.Config) – pytest config object

## Objects¶

Full reference to objects accessible from fixtures or hooks.

### CallInfo¶

class `CallInfo`[source]

Result/Exception info a function invocation.

`when` = None

context of invocation: one of “setup”, “call”, “teardown”, “memocollect”

`excinfo` = None

None or ExceptionInfo object.

### Class¶

class `Class`[source]

Bases: `_pytest.python.PyCollector`

Collector for test methods.

### Collector¶

class `Collector`[source]

Collector instances create children through collect() and thus iteratively build a tree.

exception `CollectError`[source]

Bases: `Exception`

an error during collection, contains a custom message.

`Collector.``collect`()[source]

returns a list of children (items and collectors) for this collection node.

`Collector.``repr_failure`(excinfo)[source]

represent a collection failure.

### Config¶

class `Config`[source]

`option` = None

access to command line option as attributes. (deprecated), use `getoption()` instead

`pluginmanager` = None

a pluginmanager instance

`add_cleanup`(func)[source]

Add a function to be called when the config object gets out of use (usually coninciding with pytest_unconfigure).

`warn`(code, message, fslocation=None, nodeid=None)[source]

generate a warning for this test session.

classmethod `fromdictargs`(option_dict, args)[source]

constructor useable for subprocesses.

`addinivalue_line`(name, line)[source]

add a line to an ini-file option. The option must have been declared but might not yet be set in which case the line becomes the the first line in its value.

`getini`(name)[source]

return configuration value from an ini file. If the specified name hasn’t been registered through a prior `parser.addini` call (usually from a plugin), a ValueError is raised.

`getoption`(name, default=<NOTSET>, skip=False)[source]

return command line option value.

Parameters: name – name of the option. You may also specify the literal `--OPT` option instead of the “dest” option name. default – default value if no option of that name exists. skip – if True raise pytest.skip if option does not exists or has a None value.
`getvalue`(name, path=None)[source]

(deprecated, use getoption())

`getvalueorskip`(name, path=None)[source]

(deprecated, use getoption(skip=True))

### ExceptionInfo¶

class `ExceptionInfo`(tup=None, exprinfo=None)[source]

wraps sys.exc_info() objects and offers help for navigating the traceback.

`type` = None

the exception class

`value` = None

the exception instance

`tb` = None

the exception raw traceback

`typename` = None

the exception type name

`traceback` = None

the exception traceback (_pytest._code.Traceback instance)

`exconly`(tryshort=False)[source]

return the exception as a string

when ‘tryshort’ resolves to True, and the exception is a _pytest._code._AssertionError, only the actual exception part of the exception representation is returned (so ‘AssertionError: ‘ is removed from the beginning)

`errisinstance`(exc)[source]

return True if the exception is an instance of exc

`getrepr`(showlocals=False, style='long', abspath=False, tbfilter=True, funcargs=False)[source]

return str()able representation of this exception info. showlocals: show locals per traceback entry style: long|short|no|native traceback style tbfilter: hide entries (where __tracebackhide__ is true)

in case of style==native, tbfilter and showlocals is ignored.

`match`(regexp)[source]

Match the regular expression ‘regexp’ on the string representation of the exception. If it matches then True is returned (so that it is possible to write ‘assert excinfo.match()’). If it doesn’t match an AssertionError is raised.

### FixtureDef¶

class `FixtureDef`[source]

Bases: `object`

A container for a factory definition.

### FSCollector¶

class `FSCollector`[source]

### Function¶

class `Function`[source]

Bases: `_pytest.python.FunctionMixin`, `_pytest.nodes.Item`, `_pytest.compat.FuncargnamesCompatAttr`

a Function Item is responsible for setting up and executing a Python test function.

`originalname` = None

original function name, without any decorations (for example parametrization adds a `"[...]"` suffix to function names).

New in version 3.0.

`function`

underlying python ‘function’ object

`runtest`()[source]

execute the underlying test function.

### Item¶

class `Item`[source]

a basic test invocation item. Note that for a single function there might be multiple test invocation items.

`user_properties` = None

user properties is a list of tuples (name, value) that holds user defined properties for this test.

`add_report_section`(when, key, content)[source]

Adds a new report section, similar to what’s done internally to add stdout and stderr captured output:

```item.add_report_section("call", "stdout", "report section contents")
```
Parameters: when (str) – One of the possible capture states, `"setup"`, `"call"`, `"teardown"`. key (str) – Name of the section, can be customized at will. Pytest uses `"stdout"` and `"stderr"` internally. content (str) – The full contents as a string.

### MarkDecorator¶

class `MarkDecorator`(mark)[source]

A decorator for test functions and test classes. When applied it will create `MarkInfo` objects which may be retrieved by hooks as item keywords. MarkDecorator instances are often created like this:

```mark1 = pytest.mark.NAME              # simple MarkDecorator
mark2 = pytest.mark.NAME(name1=value) # parametrized MarkDecorator
```

and can then be applied as decorators to test functions:

```@mark2
def test_function():
pass
```
When a MarkDecorator instance is called it does the following:
1. If called with a single class as its only positional argument and no additional keyword arguments, it attaches itself to the class so it gets applied automatically to all test cases found in that class.
2. If called with a single function as its only positional argument and no additional keyword arguments, it attaches a MarkInfo object to the function, containing all the arguments already stored internally in the MarkDecorator.
3. When called in any other case, it performs a ‘fake construction’ call, i.e. it returns a new MarkDecorator instance with the original MarkDecorator’s content updated with the arguments passed to this call.

Note: The rules above prevent MarkDecorator objects from storing only a single function or class reference as their positional argument with no additional keyword or positional arguments.

`name`

alias for mark.name

`args`

alias for mark.args

`kwargs`

alias for mark.kwargs

`with_args`(*args, **kwargs)[source]

return a MarkDecorator with extra arguments added

unlike call this can be used even if the sole argument is a callable/class

Returns: MarkDecorator

### MarkGenerator¶

class `MarkGenerator`[source]

Factory for `MarkDecorator` objects - exposed as a `pytest.mark` singleton instance. Example:

```import pytest
@pytest.mark.slowtest
def test_function():
pass
```

will set a ‘slowtest’ `MarkInfo` object on the `test_function` object.

### MarkInfo¶

class `MarkInfo`(mark)[source]

Marking object created by `MarkDecorator` instances.

`name`

alias for combined.name

`args`

alias for combined.args

`kwargs`

alias for combined.kwargs

`add_mark`(mark)[source]

add a MarkInfo with the given args and kwargs.

### Metafunc¶

class `Metafunc`(function, fixtureinfo, config, cls=None, module=None)[source]

Metafunc objects are passed to the `pytest_generate_tests` hook. They help to inspect a test function and to generate tests according to test configuration or values specified in the class or module where a test function is defined.

`config` = None

access to the `_pytest.config.Config` object for the test session

`module` = None

the module object where the test function is defined in.

`function` = None

underlying python test function

`fixturenames` = None

set of fixture names required by the test function

`cls` = None

class object where the test function is defined in or `None`.

`parametrize`(argnames, argvalues, indirect=False, ids=None, scope=None)[source]

Add new invocations to the underlying test function using the list of argvalues for the given argnames. Parametrization is performed during the collection phase. If you need to setup expensive resources see about setting indirect to do it rather at test setup time.

Parameters: argnames – a comma-separated string denoting one or more argument names, or a list/tuple of argument strings. argvalues – The list of argvalues determines how often a test is invoked with different argument values. If only one argname was specified argvalues is a list of values. If N argnames were specified, argvalues must be a list of N-tuples, where each tuple-element specifies a value for its respective argname. indirect – The list of argnames or boolean. A list of arguments’ names (subset of argnames). If True the list contains all names from the argnames. Each argvalue corresponding to an argname in this list will be passed as request.param to its respective argname fixture function so that it can perform more expensive setups during the setup phase of a test rather than at collection time. ids – list of string ids, or a callable. If strings, each is corresponding to the argvalues so that they are part of the test id. If None is given as id of specific test, the automatically generated id for that argument will be used. If callable, it should take one argument (a single argvalue) and return a string or return None. If None, the automatically generated id for that argument will be used. If no ids are provided they will be generated automatically from the argvalues. scope – if specified it denotes the scope of the parameters. The scope is used for grouping tests by parameter instances. It will also override any fixture-function defined scope, allowing to set a dynamic scope using test context or configuration.
`addcall`(funcargs=None, id=<object object>, param=<object object>)[source]

Add a new call to the underlying test function during the collection phase of a test run.

Deprecated since version 3.3: Use `parametrize()` instead.

Note that request.addcall() is called during the test collection phase prior and independently to actual test execution. You should only use addcall() if you need to specify multiple arguments of a test function.

Parameters: funcargs – argument keyword dictionary used when invoking the test function. id – used for reporting and identification purposes. If you don’t supply an id an automatic unique id will be generated. param – a parameter which will be exposed to a later fixture function invocation through the `request.param` attribute.

### Module¶

class `Module`[source]

Bases: `_pytest.nodes.File`, `_pytest.python.PyCollector`

Collector for test classes and functions.

### Node¶

class `Node`[source]

base class for Collector and Item the test collection tree. Collector subclasses have children, Items are terminal nodes.

`name` = None

a unique name within the scope of the parent node

`parent` = None

the parent collector node.

`config` = None

the pytest config object

`session` = None

the session this node is part of

`fspath` = None

filesystem path where this node was collected from (can be None)

`keywords` = None

keywords/markers collected from all scopes

`extra_keyword_matches` = None

allow adding of extra keywords to use for matching

`ihook`

fspath sensitive hook proxy used to call pytest hooks

`warn`(code, message)[source]

generate a warning with the given code and message for this item.

`nodeid`

a ::-separated string denoting its collection tree address.

`listchain`()[source]

return list of all parent collectors up to self, starting from root of collection tree.

`add_marker`(marker)[source]

dynamically add a marker object to the node.

`marker` can be a string or pytest.mark.* instance.

`get_marker`(name)[source]

get a marker object from this node or None if the node doesn’t have a marker with that name.

`listextrakeywords`()[source]

Return a set of all extra keywords in self and any parents.

`addfinalizer`(fin)[source]

register a function to be called when this node is finalized.

This method can only be called when this node is active in a setup chain, for example during self.setup().

`getparent`(cls)[source]

get the next parent node (including ourself) which is an instance of the given class

### Parser¶

class `Parser`[source]

Parser for command line arguments and ini-file values.

Variables: extra_info – dict of generic param -> value to display in case there’s an error processing the command line arguments.
`getgroup`(name, description='', after=None)[source]

get (or create) a named option Group.

Name: name of the option group. long description for –help output. name of other group, used for ordering –help output.

The returned group object has an `addoption` method with the same signature as `parser.addoption` but will be shown in the respective group in the output of `pytest. --help`.

`addoption`(*opts, **attrs)[source]

register a command line option.

Opts: option names, can be short or long options. same attributes which the `add_option()` function of the argparse library accepts.

After command line parsing options are available on the pytest config object via `config.option.NAME` where `NAME` is usually set by passing a `dest` attribute, for example `addoption("--long", dest="NAME", ...)`.

`parse_known_args`(args, namespace=None)[source]

parses and returns a namespace object with known arguments at this point.

`parse_known_and_unknown_args`(args, namespace=None)[source]

parses and returns a namespace object with known arguments, and the remaining arguments unknown at this point.

`addini`(name, help, type=None, default=None)[source]

register an ini-file option.

Name: name of the ini-variable type of the variable, can be `pathlist`, `args`, `linelist` or `bool`. default value if no ini-file option exists but is queried.

The value of ini-variables can be retrieved via a call to `config.getini(name)`.

### PluginManager¶

class `PluginManager`[source]

Core Pluginmanager class which manages registration of plugin objects and 1:N hook calling.

You can register new hooks by calling `add_hookspec(module_or_class)`. You can register plugin objects (which contain hooks) by calling `register(plugin)`. The Pluginmanager is initialized with a prefix that is searched for in the names of the dict of registered plugin objects. An optional excludefunc allows to blacklist names which are not considered as hooks despite a matching prefix.

For debugging purposes you can call `enable_tracing()` which will subsequently send debug information to the trace helper.

`register`(plugin, name=None)[source]

Register a plugin and return its canonical name or None if the name is blocked from registering. Raise a ValueError if the plugin is already registered.

`unregister`(plugin=None, name=None)[source]

unregister a plugin object and all its contained hook implementations from internal data structures.

`set_blocked`(name)[source]

block registrations of the given name, unregister if already registered.

`is_blocked`(name)[source]

return True if the name blogs registering plugins of that name.

`add_hookspecs`(module_or_class)[source]

add new hook specifications defined in the given module_or_class. Functions are recognized if they have been decorated accordingly.

`get_plugins`()[source]

return the set of registered plugins.

`is_registered`(plugin)[source]

Return True if the plugin is already registered.

`get_canonical_name`(plugin)[source]

Return canonical name for a plugin object. Note that a plugin may be registered under a different name which was specified by the caller of register(plugin, name). To obtain the name of an registered plugin use `get_name(plugin)` instead.

`get_plugin`(name)[source]

Return a plugin or None for the given name.

`has_plugin`(name)[source]

Return True if a plugin with the given name is registered.

`get_name`(plugin)[source]

Return name for registered plugin or None if not registered.

`check_pending`()[source]

Verify that all hooks which have not been verified against a hook specification are optional, otherwise raise PluginValidationError

`load_setuptools_entrypoints`(entrypoint_name)[source]

Load modules from querying the specified setuptools entrypoint name. Return the number of loaded plugins.

`list_plugin_distinfo`()[source]

return list of distinfo/plugin tuples for all setuptools registered plugins.

`list_name_plugin`()[source]

return list of name/plugin pairs.

`get_hookcallers`(plugin)[source]

get all hook callers for the specified plugin.

`add_hookcall_monitoring`(before, after)[source]

add before/after tracing functions for all hooks and return an undo function which, when called, will remove the added tracers.

`before(hook_name, hook_impls, kwargs)` will be called ahead of all hook calls and receive a hookcaller instance, a list of HookImpl instances and the keyword arguments for the hook call.

`after(outcome, hook_name, hook_impls, kwargs)` receives the same arguments as `before` but also a `_Result`` object which represents the result of the overall hook call.

`enable_tracing`()[source]

enable tracing of hook calls and return an undo function.

`subset_hook_caller`(name, remove_plugins)[source]

Return a new _HookCaller instance for the named method which manages calls to all registered plugins except the ones from remove_plugins.

### PytestPluginManager¶

class `PytestPluginManager`[source]

Overwrites `pluggy.PluginManager` to add pytest-specific functionality:

• loading plugins from the command line, `PYTEST_PLUGINS` env variable and `pytest_plugins` global variables found in plugins being loaded;
• `conftest.py` loading during start-up;
`addhooks`(module_or_class)[source]

Deprecated since version 2.8.

Use `pluggy.PluginManager.add_hookspecs` instead.

`parse_hookimpl_opts`(plugin, name)[source]
`parse_hookspec_opts`(module_or_class, name)[source]
`register`(plugin, name=None)[source]
`getplugin`(name)[source]
`hasplugin`(name)[source]

Return True if the plugin with the given name is registered.

`pytest_configure`(config)[source]
`consider_preparse`(args)[source]
`consider_pluginarg`(arg)[source]
`consider_conftest`(conftestmodule)[source]
`consider_env`()[source]
`consider_module`(mod)[source]
`import_plugin`(modname)[source]

### Session¶

class `Session`[source]
exception `Interrupted`

signals an interrupted test run.

exception `Session.``Failed`

Bases: `Exception`

signals an stop as failed test run.

### TestReport¶

class `TestReport`[source]

Basic test report object (also used for setup and teardown calls if they fail).

`nodeid` = None

normalized collection node id

`location` = None

a (filesystempath, lineno, domaininfo) tuple indicating the actual location of a test item - it might be different from the collected one e.g. if a method is inherited from a different module.

`keywords` = None

a name -> value dictionary containing all keywords and markers associated with a test invocation.

`outcome` = None

test outcome, always one of “passed”, “failed”, “skipped”.

`longrepr` = None

None or a failure representation.

`when` = None

one of ‘setup’, ‘call’, ‘teardown’ to indicate runtest phase.

`user_properties` = None

user properties is a list of tuples (name, value) that holds user defined properties of the test

`sections` = None

list of pairs `(str, str)` of extra information which needs to marshallable. Used by pytest to add captured text from `stdout` and `stderr`, but may be used by other plugins to add arbitrary information to reports.

`duration` = None

time it took to run just the test

`caplog`

Return captured log lines, if log capturing is enabled

New in version 3.5.

`capstderr`

Return captured text from stderr, if capturing is enabled

New in version 3.0.

`capstdout`

Return captured text from stdout, if capturing is enabled

New in version 3.0.

`longreprtext`

Read-only property that returns the full string representation of `longrepr`.

New in version 3.0.

### _Result¶

class `_Result`(result, excinfo)[source]
`result`

Get the result(s) for this hook call (DEPRECATED in favor of `get_result()`).

`force_result`(result)[source]

Force the result(s) to `result`.

If the hook was marked as a `firstresult` a single value should be set otherwise set a (modified) list of results. Any exceptions found during invocation will be deleted.

`get_result`()[source]

Get the result(s) for this hook call.

If the hook was marked as a `firstresult` only a single value will be returned otherwise a list of results.

## Special Variables¶

pytest treats some global variables in a special manner when defined in a test module.

### pytest_plugins¶

Can be declared at the global level in test modules and conftest.py files to register additional plugins. Can be either a `str` or `Sequence[str]`.

```pytest_plugins = "myapp.testsupport.myplugin"
```
```pytest_plugins = ("myapp.testsupport.tools", "myapp.testsupport.regression")
```

### pytest_mark¶

Tutorial: Marking whole classes or modules

Can be declared at the global level in test modules to apply one or more marks to all test functions and methods. Can be either a single mark or a sequence of marks.

```import pytest
pytestmark = pytest.mark.webtest
```
```import pytest
pytestmark = (pytest.mark.integration, pytest.mark.slow)
```

### PYTEST_DONT_REWRITE (module docstring)¶

The text `PYTEST_DONT_REWRITE` can be add to any module docstring to disable assertion rewriting for that module.

## Environment Variables¶

Environment variables that can be used to change pytest’s behavior.

This contains a command-line (parsed by the py:mod:shlex module) that will be prepended to the command line given by the user, see How to change command line options defaults for more information.

### PYTEST_DEBUG¶

When set, pytest will print tracing and debug information.

### PYTEST_PLUGINS¶

Contains comma-separated list of modules that should be loaded as plugins:

```export PYTEST_PLUGINS=mymodule.plugin,xdisst
```

### PYTEST_CURRENT_TEST¶

This is not meant to be set by users, but is set by pytest internally with the name of the current test so other processes can inspect it, see PYTEST_CURRENT_TEST environment variable for more information.

## Configuration Options¶

Here is a list of builtin configuration options that may be written in a `pytest.ini`, `tox.ini` or `setup.cfg` file, usually located at the root of your repository. All options must be under a `[pytest]` section (`[tool:pytest]` for `setup.cfg` files).

Configuration file options may be overwritten in the command-line by using `-o/--override`, which can also be passed multiple times. The expected format is `name=value`. For example:

```pytest -o console_output_style=classic -o cache_dir=/tmp/mycache
```
`addopts`

Add the specified `OPTS` to the set of command line arguments as if they had been specified by the user. Example: if you have this ini file content:

```# content of pytest.ini
[pytest]
addopts = --maxfail=2 -rf  # exit after 2 failures, report fail info
```

issuing `pytest test_hello.py` actually means:

```pytest --maxfail=2 -rf test_hello.py
```

Default is to add no options.

`cache_dir`

New in version 3.2.

Sets a directory where stores content of cache plugin. Default directory is `.cache` which is created in rootdir. Directory may be relative or absolute path. If setting relative path, then directory is created relative to rootdir. Additionally path may contain environment variables, that will be expanded. For more information about cache plugin please refer to Cache: working with cross-testrun state.

`confcutdir`

Sets a directory where search upwards for `conftest.py` files stops. By default, pytest will stop searching for `conftest.py` files upwards from `pytest.ini`/`tox.ini`/`setup.cfg` of the project if any, or up to the file-system root.

`console_output_style`

New in version 3.3.

Sets the console output style while running tests:

• `classic`: classic pytest output.
• `progress`: like classic pytest output, but with a progress indicator.

The default is `progress`, but you can fallback to `classic` if you prefer or the new mode is causing unexpected problems:

```# content of pytest.ini
[pytest]
console_output_style = classic
```
`doctest_encoding`

New in version 3.1.

Default encoding to use to decode text files with docstrings. See how pytest handles doctests.

`doctest_optionflags`

One or more doctest flag names from the standard `doctest` module. See how pytest handles doctests.

`empty_parameter_set_mark`

New in version 3.4.

Allows to pick the action for empty parametersets in parameterization

• `skip` skips tests with a empty parameterset (default)
• `xfail` marks tests with a empty parameterset as xfail(run=False)
```# content of pytest.ini
[pytest]
empty_parameter_set_mark = xfail
```

Note

The default value of this option is planned to change to `xfail` in future releases as this is considered less error prone, see #3155 for more details.

`filterwarnings`

New in version 3.1.

Sets a list of filters and actions that should be taken for matched warnings. By default all warnings emitted during the test session will be displayed in a summary at the end of the test session.

```# content of pytest.ini
[pytest]
filterwarnings =
error
ignore::DeprecationWarning
```

This tells pytest to ignore deprecation warnings and turn all other warnings into errors. For more information please refer to Warnings Capture.

`junit_suite_name`

New in version 3.1.

To set the name of the root test suite xml item, you can configure the `junit_suite_name` option in your config file:

```[pytest]
junit_suite_name = my_suite
```
`log_cli_date_format`

New in version 3.3.

Sets a `time.strftime()`-compatible string that will be used when formatting dates for live logging.

```[pytest]
log_cli_date_format = %Y-%m-%d %H:%M:%S
```

`log_cli_format`

New in version 3.3.

Sets a `logging`-compatible string used to format live logging messages.

```[pytest]
log_cli_format = %(asctime)s %(levelname)s %(message)s
```

`log_cli_level`

New in version 3.3.

Sets the minimum log message level that should be captured for live logging. The integer value or the names of the levels can be used.

```[pytest]
log_cli_level = INFO
```

`log_date_format`

New in version 3.3.

Sets a `time.strftime()`-compatible string that will be used when formatting dates for logging capture.

```[pytest]
log_date_format = %Y-%m-%d %H:%M:%S
```

`log_file`

New in version 3.3.

Sets a file name relative to the `pytest.ini` file where log messages should be written to, in addition to the other logging facilities that are active.

```[pytest]
log_file = logs/pytest-logs.txt
```

`log_file_date_format`

New in version 3.3.

Sets a `time.strftime()`-compatible string that will be used when formatting dates for the logging file.

```[pytest]
log_file_date_format = %Y-%m-%d %H:%M:%S
```

`log_file_format`

New in version 3.3.

Sets a `logging`-compatible string used to format logging messages redirected to the logging file.

```[pytest]
log_file_format = %(asctime)s %(levelname)s %(message)s
```

`log_file_level`

New in version 3.3.

Sets the minimum log message level that should be captured for the logging file. The integer value or the names of the levels can be used.

```[pytest]
log_file_level = INFO
```

`log_format`

New in version 3.3.

Sets a `logging`-compatible string used to format captured logging messages.

```[pytest]
log_format = %(asctime)s %(levelname)s %(message)s
```

`log_level`

New in version 3.3.

Sets the minimum log message level that should be captured for logging capture. The integer value or the names of the levels can be used.

```[pytest]
log_level = INFO
```

`log_print`

New in version 3.3.

If set to `False`, will disable displaying captured logging messages for failed tests.

```[pytest]
log_print = False
```

`markers`

List of markers that are allowed in test functions, enforced when `--strict` command-line argument is used. You can use a marker name per line, indented from the option name.

```[pytest]
markers =
slow
serial
```
`minversion`

Specifies a minimal pytest version required for running tests.

```# content of pytest.ini
[pytest]
minversion = 3.0  # will fail if we run with pytest-2.8
```
`norecursedirs`

Set the directory basename patterns to avoid when recursing for test discovery. The individual (fnmatch-style) patterns are applied to the basename of a directory to decide if to recurse into it. Pattern matching characters:

```*       matches everything
?       matches any single character
[seq]   matches any character in seq
[!seq]  matches any char not in seq
```

Default patterns are `'.*', 'build', 'dist', 'CVS', '_darcs', '{arch}', '*.egg', 'venv'`. Setting a `norecursedirs` replaces the default. Here is an example of how to avoid certain directories:

```[pytest]
norecursedirs = .svn _build tmp*
```

This would tell `pytest` to not look into typical subversion or sphinx-build directories or into any `tmp` prefixed directory.

Additionally, `pytest` will attempt to intelligently identify and ignore a virtualenv by the presence of an activation script. Any directory deemed to be the root of a virtual environment will not be considered during test collection unless `‑‑collect‑in‑virtualenv` is given. Note also that `norecursedirs` takes precedence over `‑‑collect‑in‑virtualenv`; e.g. if you intend to run tests in a virtualenv with a base directory that matches `'.*'` you must override `norecursedirs` in addition to using the `‑‑collect‑in‑virtualenv` flag.

`python_classes`

One or more name prefixes or glob-style patterns determining which classes are considered for test collection. By default, pytest will consider any class prefixed with `Test` as a test collection. Here is an example of how to collect tests from classes that end in `Suite`:

```[pytest]
python_classes = *Suite
```

Note that `unittest.TestCase` derived classes are always collected regardless of this option, as `unittest`‘s own collection framework is used to collect those tests.

`python_files`

One or more Glob-style file patterns determining which python files are considered as test modules. By default, pytest will consider any file matching with `test_*.py` and `*_test.py` globs as a test module.

`python_functions`

One or more name prefixes or glob-patterns determining which test functions and methods are considered tests. By default, pytest will consider any function prefixed with `test` as a test. Here is an example of how to collect test functions and methods that end in `_test`:

```[pytest]
python_functions = *_test
```

Note that this has no effect on methods that live on a ```unittest .TestCase``` derived class, as `unittest`‘s own collection framework is used to collect those tests.

See Changing naming conventions for more detailed examples.

`testpaths`

New in version 2.8.

Sets list of directories that should be searched for tests when no specific directories, files or test ids are given in the command line when executing pytest from the rootdir directory. Useful when all project tests are in a known location to speed up test collection and to avoid picking up undesired tests by accident.

```[pytest]
testpaths = testing doc
```

This tells pytest to only look for tests in `testing` and `doc` directories when executing from the root directory.

`usefixtures`

List of fixtures that will be applied to all test functions; this is semantically the same to apply the `@pytest.mark.usefixtures` marker to all test functions.

```[pytest]
usefixtures =
clean_db
```
`xfail_strict`

If set to `True`, tests marked with `@pytest.mark.xfail` that actually succeed will by default fail the test suite. For more information, see strict parameter.

```[pytest]
xfail_strict = True
```