.. Licensed under the Apache License: http://www.apache.org/licenses/LICENSE-2.0
.. For details: https://github.com/nedbat/coveragepy/blob/master/NOTICE.txt

.. This file is processed with cog to create the tabbed multi-syntax
   configuration examples.  If those are wrong, the quality checks will fail.
   Running "make prebuild" checks them and produces the output.

.. [[[cog
    from cog_helpers import show_configs
.. ]]]
.. [[[end]]] (checksum: d41d8cd98f00b204e9800998ecf8427e)


.. _excluding:

===============================
Excluding code from coverage.py
===============================

.. highlight:: python

You may have code in your project that you know won't be executed, and you want
to tell coverage.py to ignore it.  For example, you may have debugging-only
code that won't be executed during your unit tests. You can tell coverage.py to
exclude this code during reporting so that it doesn't clutter your reports with
noise about code that you don't need to hear about.

Coverage.py will look for comments marking clauses for exclusion.  In this
code, the "if debug" clause is excluded from reporting::

    a = my_function1()
    if debug:  # pragma: no cover
        msg = "blah blah"
        log_message(msg, a)
    b = my_function2()

Any line with a comment of "pragma: no cover" is excluded.  If that line
introduces a clause, for example, an if clause, or a function or class
definition, then the entire clause is also excluded.  Here the __repr__
function is not reported as missing::

    class MyObject(object):
        def __init__(self):
            blah1()
            blah2()

        def __repr__(self):  # pragma: no cover
            return "<MyObject>"

Excluded code is executed as usual, and its execution is recorded in the
coverage data as usual. When producing reports though, coverage.py excludes it
from the list of missing code.


Branch coverage
---------------

When measuring :ref:`branch coverage <branch>`, a conditional will not be
counted as a branch if one of its choices is excluded::

    def only_one_choice(x):
        if x:
            blah1()
            blah2()
        else:  # pragma: no cover
            # x is always true.
            blah3()

Because the ``else`` clause is excluded, the ``if`` only has one possible next
line, so it isn't considered a branch at all.


Advanced exclusion
------------------

Coverage.py identifies exclusions by matching lines against a list of regular
expressions. Using :ref:`configuration files <config>` or the coverage
:ref:`API <api>`, you can add to that list. This is useful if you have
often-used constructs to exclude that can be matched with a regex. You can
exclude them all at once without littering your code with exclusion pragmas.

If the matched line introduces a block, the entire block is excluded from
reporting.  Matching a ``def`` line or decorator line will exclude an entire
function.

.. highlight:: ini

For example, you might decide that __repr__ functions are usually only used in
debugging code, and are uninteresting to test themselves.  You could exclude
all of them by adding a regex to the exclusion list:

.. [[[cog
    show_configs(
        ini=r"""
            [report]
            exclude_also =
                def __repr__
            """,
        toml=r"""
            [tool.coverage.report]
            exclude_also = [
                "def __repr__",
                ]
            """,
        )
.. ]]]

.. tabs::

    .. code-tab:: ini
        :caption: .coveragerc

        [report]
        exclude_also =
            def __repr__

    .. code-tab:: toml
        :caption: pyproject.toml

        [tool.coverage.report]
        exclude_also = [
            "def __repr__",
            ]

    .. code-tab:: ini
        :caption: setup.cfg, tox.ini

        [coverage:report]
        exclude_also =
            def __repr__

.. [[[end]]] (checksum: adc6406467518c89a5a6fe2c4b999416)

For example, here's a list of exclusions I've used:

.. [[[cog
    show_configs(
        ini=r"""
            [report]
            exclude_also =
                def __repr__
                if self.debug:
                if settings.DEBUG
                raise AssertionError
                raise NotImplementedError
                if 0:
                if __name__ == .__main__.:
                if TYPE_CHECKING:
                class .*\bProtocol\):
                @(abc\.)?abstractmethod
            """,
        toml=r"""
            [tool.coverage.report]
            exclude_also = [
                "def __repr__",
                "if self.debug:",
                "if settings.DEBUG",
                "raise AssertionError",
                "raise NotImplementedError",
                "if 0:",
                "if __name__ == .__main__.:",
                "if TYPE_CHECKING:",
                "class .*\\bProtocol\\):",
                "@(abc\\.)?abstractmethod",
                ]
            """,
        )
.. ]]]

.. tabs::

    .. code-tab:: ini
        :caption: .coveragerc

        [report]
        exclude_also =
            def __repr__
            if self.debug:
            if settings.DEBUG
            raise AssertionError
            raise NotImplementedError
            if 0:
            if __name__ == .__main__.:
            if TYPE_CHECKING:
            class .*\bProtocol\):
            @(abc\.)?abstractmethod

    .. code-tab:: toml
        :caption: pyproject.toml

        [tool.coverage.report]
        exclude_also = [
            "def __repr__",
            "if self.debug:",
            "if settings.DEBUG",
            "raise AssertionError",
            "raise NotImplementedError",
            "if 0:",
            "if __name__ == .__main__.:",
            "if TYPE_CHECKING:",
            "class .*\\bProtocol\\):",
            "@(abc\\.)?abstractmethod",
            ]

    .. code-tab:: ini
        :caption: setup.cfg, tox.ini

        [coverage:report]
        exclude_also =
            def __repr__
            if self.debug:
            if settings.DEBUG
            raise AssertionError
            raise NotImplementedError
            if 0:
            if __name__ == .__main__.:
            if TYPE_CHECKING:
            class .*\bProtocol\):
            @(abc\.)?abstractmethod

.. [[[end]]] (checksum: ef1947821b8224c4f02d27f9514e5c5e)

The :ref:`config_report_exclude_also` option adds regexes to the built-in
default list so that you can add your own exclusions.  The older
:ref:`config_report_exclude_lines` option completely overwrites the list of
regexes.

The regexes only have to match part of a line. Be careful not to over-match.  A
value of ``...`` will match any line with more than three characters in it.

A similar pragma, "no branch", can be used to tailor branch coverage
measurement.  See :ref:`branch` for details.


Excluding source files
----------------------

See :ref:`source` for ways to limit what files coverage.py measures or reports
on.
