

Basic patterns and examples
==========================================================

How to change command line options defaults
-------------------------------------------

It can be tedious to type the same series of command line options
every time you use ``pytest``.  For example, if you always want to see
detailed info on skipped and xfailed tests, as well as have terser "dot"
progress output, you can write it into a configuration file:

.. code-block:: ini

    # content of pytest.ini
    [pytest]
    addopts = -ra -q


Alternatively, you can set a ``PYTEST_ADDOPTS`` environment variable to add command
line options while the environment is in use:

.. code-block:: bash

    export PYTEST_ADDOPTS="-v"

Here's how the command-line is built in the presence of ``addopts`` or the environment variable:

.. code-block:: text

    <pytest.ini:addopts> $PYTEST_ADDOPTS <extra command-line arguments>

So if the user executes in the command-line:

.. code-block:: bash

    pytest -m slow

The actual command line executed is:

.. code-block:: bash

    pytest -ra -q -v -m slow

Note that as usual for other command-line applications, in case of conflicting options the last one wins, so the example
above will show verbose output because ``-v`` overwrites ``-q``.


.. _request example:

Pass different values to a test function, depending on command line options
----------------------------------------------------------------------------

.. regendoc:wipe

Suppose we want to write a test that depends on a command line                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    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