How to suppress py.test internal deprecation warnings

pytest -p no:warnings, or add the following to your pytest.ini or tox.ini:

[pytest]
addopts = -p no:warnings

The result will be green without any indication of warnings. See documentation at https://docs.pytest.org/en/latest/warnings.html#disabling-warnings-summary.

This can be a valid use case for a test suite where you want clean output.

Be aware that always hiding all warnings may cause you to miss important warnings. If you want to hide only specific warnings, look at Cloc’s answer.

I think you do not want to hide all warnings, but just the ones that are not relevant. And in this case, deprectation warnings from imported python modules.

Having a read on pytest documentation about Warnings Capture:

Both -W command-line option and filterwarnings ini option are based on Python’s own -W option and warnings.simplefilter, so please refer to those sections in the Python documentation for other examples and advanced usage.

So you can filter warnings with python’s -W option!

It seems that pytest completely removes filters, because it shows all those DeprecationWarning when running, and Python’s documentation about Default Warning Filters clearly says:

In regular release builds, the default warning filter has the
following entries (in order of precedence):

default::DeprecationWarning:__main__
ignore::DeprecationWarning
ignore::PendingDeprecationWarning
ignore::ImportWarning
ignore::ResourceWarning

So in your case, if you want let say to filter types of warning you want to ignore, such as those DeprecationWarning, just run the pytest command with -W option :

$ pytest path-to-test-folder -W ignore::DeprecationWarning

EDIT: From colini‘s comment, it is possible to filter by module. Example to ignore deprecation warnings from all sqlalchemy :

ignore::DeprecationWarning:sqlalchemy.*:

You can then list your installed modules that creates too much noise in the output of pytest

EDIT2: For more precise control, the Python documentation about Describing Warning Filters states that the general way to write such warning filters is:

action:message:category:module:line

Use with file rather than in command line:

You may prefer list those filters in pytest.ini file :

[pytest]
filterwarnings =
    ignore::DeprecationWarning

I don’t want to hide all warning, so I put this in pytest.ini

[pytest]
filterwarnings =
    ignore::DeprecationWarning

In the pytest.ini file you can add:

[pytest]
addopts = -p no:warnings

OR passing below line in the command-line. This might be useful if your test suites handle warnings using an external system.

-p no:warnings

OR if you only want to hide some specific deprecated warning, add below statement in you pytest.ini file

[pytest]
filterwarnings =
    ignore:.*U.*mode is deprecated:DeprecationWarning

This will ignore all warnings of type DeprecationWarning where the start of the message matches the regular expression “.*U.*mode is deprecated”.

OR Although not recommended, you can use the

–disable-warnings

command-line option to suppress the warning summary entirely from the test run output.

Here is a link for how to suppress warnings if you are using pyproject.toml file as configuration.

[tool.pytest.ini_options]
testpaths = ["./tests/unit"]
filterwarnings = ["ignore:::.*third_party_package.module:123", "ignore:::.*another_module*"]

123 in this case is a line number to be suppressed

For more information on the general way to write warning filters, see the python official doc at "The Warnings Filter" and "Describing Warning Filters".
In short, Individual warnings filters are specified as a sequence of fields separated by colons: action:message:category:module:line

If you use a setup.cfg file, put this in:

[tool:pytest]
addopts = -p no:warnings

You need tool:pytest instead of just pytest, but it will tell you:

Failed: [pytest] section in setup.cfg files is no longer supported, change to [tool:pytest] instead.

I want to add that it is also possible to filter the warnings in a fine-granular way by understanding the parsing mechanism which is well explained in the warnings section of the python documentation.

Individual warnings filters are specified as a sequence of fields separated by colons:
action:message:category:module:line

This allows you to e.g. disable a specific warning with a specific message for a specific module only. For me, it was using pytest-freezegun, but not showing the annoying DeprecationWarning for using distutils Version classes.

Without applying the described filter from below the relevant output part from pytest runner is:

.venv/lib/python3.11/site-packages/pytest_freezegun.py:17: 34 warnings
tests/test_folder1/test_1.py: 10 warnings
tests/test_folder1/test_2.py: 4 warnings
  /my/project/path/.venv/lib/python3.11/site-packages/pytest_freezegun.py:17: DeprecationWarning: distutils Version classes are deprecated. Use packaging.version instead.
    if LooseVersion(pytest.__version__) < LooseVersion('3.6.0'):

-- Docs: https://docs.pytest.org/en/stable/how-to/capture-warnings.html

And with this setting in pyproject.toml, the DeprecationWarning for not using packaging.version is completely gone, but only for pytest-freezegun (because I do not want to deactivate all deprecation warnings for the whole project):

[tool.pytest.ini_options]
testpaths = ["./tests"]
filterwarnings = ["ignore:.*distutils Version classes.*packaging.version:DeprecationWarning:pytest_freezegun"]

In detail:

ignore:.*distutils Version classes.*packaging.version:DeprecationWarning:pytest_freezegun
^^^^^^ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ^^^^^^^^^^^^^^^^^^ ^^^^^^^^^^^^^^^^
action       message (regular expression)                  category           module                                                  

Note: I do not want to include the line number, because library code could be changed without fixing the DeprecationWarning.

(The possibility of filtering has also been mentioned in a comment, but I wanted to elaborate a little more.)

${PYTHON} -m pytest -W ignore::DeprecationWarning

DeprecationWarning Will help remove the imports decrecations warning coming up when we run pytest .

This can be used in makefile.py to ignore the warnings

If you’d like to ignore all the warnings from the pytest file itself.
Just add the following in your pytest file:

import warnings; warnings.filterwarnings("ignore")

when working with multiple warnings,

python -m pytest -W ignore::DeprecationWarning -W ignore::ImportWarning