Deprecations and Removals¶
This page lists all pytest features that are currently deprecated or have been removed in past major releases. The objective is to give users a clear rationale why a certain feature has been removed, and what alternatives should be used instead.
- Deprecated Features
- Removed Features
pytest.config
global"message"
parameter ofpytest.raises
raises
/warns
with a string as the second argument- Using
Class
in custom Collectors - marks in
pytest.mark.parametrize
pytest_funcarg__
prefix- [pytest] section in setup.cfg files
- Metafunc.addcall
cached_setup
- pytest_plugins in non-top-level conftest files
Config.warn
andNode.warn
- record_xml_property
- Passing command-line string to
pytest.main()
- Calling fixtures directly
yield
tests- Internal classes accessed through
Node
Node.get_marker
somefunction.markname
pytest_namespace
- Reinterpretation mode (
--assert=reinterp
) - Removed command-line options
- py.test-X* entry points
Deprecated Features¶
Below is a complete list of all pytest features which are considered deprecated. Using those features will issue
_pytest.warning_types.PytestWarning
or subclasses, which can be filtered using
standard warning filters.
junit_family
default value change to “xunit2”¶
Deprecated since version 5.2.
The default value of junit_family
option will change to xunit2
in pytest 6.0, given
that this is the version supported by default in modern tools that manipulate this type of file.
In order to smooth the transition, pytest will issue a warning in case the --junitxml
option
is given in the command line but junit_family
is not explicitly configured in pytest.ini
:
PytestDeprecationWarning: The 'junit_family' default value will change to 'xunit2' in pytest 6.0.
Add 'junit_family=legacy' to your pytest.ini file to silence this warning and make your suite compatible.
In order to silence this warning, users just need to configure the junit_family
option explicitly:
[pytest]
junit_family=legacy
funcargnames
alias for fixturenames
¶
Deprecated since version 5.0.
The FixtureRequest
, Metafunc
, and Function
classes track the names of
their associated fixtures, with the aptly-named fixturenames
attribute.
Prior to pytest 2.3, this attribute was named funcargnames
, and we have kept
that as an alias since. It is finally due for removal, as it is often confusing
in places where we or plugin authors must distinguish between fixture names and
names supplied by non-fixture things such as pytest.mark.parametrize
.
Result log (--result-log
)¶
Deprecated since version 4.0.
The --result-log
option produces a stream of test reports which can be
analysed at runtime, but it uses a custom format which requires users to implement their own
parser.
The pytest-reportlog plugin provides a --report-log
option, a more standard and extensible alternative, producing
one JSON object per-line, and should cover the same use cases. Please try it out and provide feedback.
The plan is remove the --result-log
option in pytest 6.0 if pytest-reportlog
proves satisfactory
to all users and is deemed stable. The pytest-reportlog
plugin might even be merged into the core
at some point, depending on the plans for the plugins and number of users using it.
Removed Features¶
As stated in our Backwards Compatibility Policy policy, deprecated features are removed only in major releases after an appropriate period of deprecation has passed.
pytest.config
global¶
Removed in version 5.0.
The pytest.config
global object is deprecated. Instead use
request.config
(via the request
fixture) or if you are a plugin author
use the pytest_configure(config)
hook. Note that many hooks can also access
the config
object indirectly, through session.config
or item.config
for example.
"message"
parameter of pytest.raises
¶
Removed in version 5.0.
It is a common mistake to think this parameter will match the exception message, while in fact
it only serves to provide a custom message in case the pytest.raises
check fails. To prevent
users from making this mistake, and because it is believed to be little used, pytest is
deprecating it without providing an alternative for the moment.
If you have a valid use case for this parameter, consider that to obtain the same results
you can just call pytest.fail
manually at the end of the with
statement.
For example:
with pytest.raises(TimeoutError, message="Client got unexpected message"):
wait_for(websocket.recv(), 0.5)
Becomes:
with pytest.raises(TimeoutError):
wait_for(websocket.recv(), 0.5)
pytest.fail("Client got unexpected message")
If you still have concerns about this deprecation and future removal, please comment on issue #3974.
raises
/ warns
with a string as the second argument¶
Removed in version 5.0.
Use the context manager form of these instead. When necessary, invoke exec
directly.
Example:
pytest.raises(ZeroDivisionError, "1 / 0")
pytest.raises(SyntaxError, "a $ b")
pytest.warns(DeprecationWarning, "my_function()")
pytest.warns(SyntaxWarning, "assert(1, 2)")
Becomes:
with pytest.raises(ZeroDivisionError):
1 / 0
with pytest.raises(SyntaxError):
exec("a $ b") # exec is required for invalid syntax
with pytest.warns(DeprecationWarning):
my_function()
with pytest.warns(SyntaxWarning):
exec("assert(1, 2)") # exec is used to avoid a top-level warning
Using Class
in custom Collectors¶
Removed in version 4.0.
Using objects named "Class"
as a way to customize the type of nodes that are collected in Collector
subclasses has been deprecated. Users instead should use pytest_pycollect_makeitem
to customize node types during
collection.
This issue should affect only advanced plugins who create new collection types, so if you see this warning message please contact the authors so they can change the code.
marks in pytest.mark.parametrize
¶
Removed in version 4.0.
Applying marks to values of a pytest.mark.parametrize
call is now deprecated. For example:
@pytest.mark.parametrize(
"a, b",
[
(3, 9),
pytest.mark.xfail(reason="flaky")(6, 36),
(10, 100),
(20, 200),
(40, 400),
(50, 500),
],
)
def test_foo(a, b):
...
This code applies the pytest.mark.xfail(reason="flaky")
mark to the (6, 36)
value of the above parametrization
call.
This was considered hard to read and understand, and also its implementation presented problems to the code preventing further internal improvements in the marks architecture.
To update the code, use pytest.param
:
@pytest.mark.parametrize(
"a, b",
[
(3, 9),
pytest.param(6, 36, marks=pytest.mark.xfail(reason="flaky")),
(10, 100),
(20, 200),
(40, 400),
(50, 500),
],
)
def test_foo(a, b):
...
pytest_funcarg__
prefix¶
Removed in version 4.0.
In very early pytest versions fixtures could be defined using the pytest_funcarg__
prefix:
def pytest_funcarg__data():
return SomeData()
Switch over to the @pytest.fixture
decorator:
@pytest.fixture
def data():
return SomeData()
[pytest] section in setup.cfg files¶
Removed in version 4.0.
[pytest]
sections in setup.cfg
files should now be named [tool:pytest]
to avoid conflicts with other distutils commands.
Metafunc.addcall¶
Removed in version 4.0.
_pytest.python.Metafunc.addcall()
was a precursor to the current parametrized mechanism. Users should use
_pytest.python.Metafunc.parametrize()
instead.
Example:
def pytest_generate_tests(metafunc):
metafunc.addcall({"i": 1}, id="1")
metafunc.addcall({"i": 2}, id="2")
Becomes:
def pytest_generate_tests(metafunc):
metafunc.parametrize("i", [1, 2], ids=["1", "2"])
cached_setup
¶
Removed in version 4.0.
request.cached_setup
was the precursor of the setup/teardown mechanism available to fixtures.
Example:
@pytest.fixture
def db_session():
return request.cached_setup(
setup=Session.create, teardown=lambda session: session.close(), scope="module"
)
This should be updated to make use of standard fixture mechanisms:
@pytest.fixture(scope="module")
def db_session():
session = Session.create()
yield session
session.close()
You can consult funcarg comparison section in the docs for more information.
pytest_plugins in non-top-level conftest files¶
Removed in version 4.0.
Defining pytest_plugins
is now deprecated in non-top-level conftest.py
files because they will activate referenced plugins globally, which is surprising because for all other pytest
features conftest.py
files are only active for tests at or below it.
Config.warn
and Node.warn
¶
Removed in version 4.0.
Those methods were part of the internal pytest warnings system, but since 3.8
pytest is using the builtin warning
system for its own warnings, so those two functions are now deprecated.
Config.warn
should be replaced by calls to the standard warnings.warn
, example:
config.warn("C1", "some warning")
Becomes:
warnings.warn(pytest.PytestWarning("some warning"))
Node.warn
now supports two signatures:
node.warn(PytestWarning("some message"))
: is now the recommended way to call this function. The warning instance must be a PytestWarning or subclass.node.warn("CI", "some message")
: this code/message form has been removed and should be converted to the warning instance form above.
record_xml_property¶
Removed in version 4.0.
The record_xml_property
fixture is now deprecated in favor of the more generic record_property
, which
can be used by other consumers (for example pytest-html
) to obtain custom information about the test run.
This is just a matter of renaming the fixture as the API is the same:
def test_foo(record_xml_property):
...
Change to:
def test_foo(record_property):
...
Passing command-line string to pytest.main()
¶
Removed in version 4.0.
Passing a command-line string to pytest.main()
is deprecated:
pytest.main("-v -s")
Pass a list instead:
pytest.main(["-v", "-s"])
By passing a string, users expect that pytest will interpret that command-line using the shell rules they are working
on (for example bash
or Powershell
), but this is very hard/impossible to do in a portable way.
Calling fixtures directly¶
Removed in version 4.0.
Calling a fixture function directly, as opposed to request them in a test function, is deprecated.
For example:
@pytest.fixture
def cell():
return ...
@pytest.fixture
def full_cell():
cell = cell()
cell.make_full()
return cell
This is a great source of confusion to new users, which will often call the fixture functions and request them from test functions interchangeably, which breaks the fixture resolution model.
In those cases just request the function directly in the dependent fixture:
@pytest.fixture
def cell():
return ...
@pytest.fixture
def full_cell(cell):
cell.make_full()
return cell
Alternatively if the fixture function is called multiple times inside a test (making it hard to apply the above pattern) or
if you would like to make minimal changes to the code, you can create a fixture which calls the original function together
with the name
parameter:
def cell():
return ...
@pytest.fixture(name="cell")
def cell_fixture():
return cell()
yield
tests¶
Removed in version 4.0.
pytest supported yield
-style tests, where a test function actually yield
functions and values
that are then turned into proper test methods. Example:
def check(x, y):
assert x ** x == y
def test_squared():
yield check, 2, 4
yield check, 3, 9
This would result into two actual test functions being generated.
This form of test function doesn’t support fixtures properly, and users should switch to pytest.mark.parametrize
:
@pytest.mark.parametrize("x, y", [(2, 4), (3, 9)])
def test_squared(x, y):
assert x ** x == y
Internal classes accessed through Node
¶
Removed in version 4.0.
Access of Module
, Function
, Class
, Instance
, File
and Item
through Node
instances now issue
this warning:
usage of Function.Module is deprecated, please use pytest.Module instead
Users should just import pytest
and access those objects using the pytest
module.
This has been documented as deprecated for years, but only now we are actually emitting deprecation warnings.
Node.get_marker
¶
Removed in version 4.0.
As part of a large Marker revamp and iteration, _pytest.nodes.Node.get_marker()
is deprecated. See
the documentation on tips on how to update your code.
somefunction.markname
¶
Removed in version 4.0.
As part of a large Marker revamp and iteration we already deprecated using MarkInfo
the only correct way to get markers of an element is via node.iter_markers(name)
.
pytest_namespace
¶
Removed in version 4.0.
This hook is deprecated because it greatly complicates the pytest internals regarding configuration and initialization, making some bug fixes and refactorings impossible.
Example of usage:
class MySymbol:
...
def pytest_namespace():
return {"my_symbol": MySymbol()}
Plugin authors relying on this hook should instead require that users now import the plugin modules directly (with an appropriate public API).
As a stopgap measure, plugin authors may still inject their names into pytest’s namespace, usually during pytest_configure
:
import pytest
def pytest_configure():
pytest.my_symbol = MySymbol()
Reinterpretation mode (--assert=reinterp
)¶
Removed in version 3.0.
Reinterpretation mode has now been removed and only plain and rewrite
mode are available, consequently the --assert=reinterp
option is
no longer available. This also means files imported from plugins or
conftest.py
will not benefit from improved assertions by
default, you should use pytest.register_assert_rewrite()
to
explicitly turn on assertion rewriting for those files.
Removed command-line options¶
Removed in version 3.0.
The following deprecated commandline options were removed:
--genscript
: no longer supported;--no-assert
: use--assert=plain
instead;--nomagic
: use--assert=plain
instead;--report
: use-r
instead;
py.test-X* entry points¶
Removed in version 3.0.
Removed all py.test-X*
entry points. The versioned, suffixed entry points
were never documented and a leftover from a pre-virtualenv era. These entry
points also created broken entry points in wheels, so removing them also
removes a source of confusion for users.