collect and run doctests from modules and test files.
=========================================================

By default all files matching the ``test*.txt`` pattern will
be run through the python standard ``doctest`` module.  You
can change the pattern by issuing::

    py.test --doctest-glob='*.rst'

on the command line.  You can also trigger running of doctests
from docstrings in all python modules (including regular
python test modules)::

    py.test --doctest-modules

You can make these changes permanent in your project by
putting them into a conftest.py file like this::

    # content of conftest.py
    option_doctestmodules = True
    option_doctestglob = "*.rst"

If you then have a text file like this::

    # content of example.rst

    hello this is a doctest
    >>> x = 3
    >>> x
    3

and another like this::

    # content of mymodule.py
    def something():
        """ a doctest in a docstring
        >>> something()  
        42
        """
        return 42

then you can just invoke ``py.test`` without command line options::

    $ py.test
    ============================= test session starts ==============================
    platform linux2 -- Python 2.6.5 -- pytest-2.0.0dev0
    test path 1: /tmp/doc-exec-109
    
    conftest.py .
    example.rst .
    mymodule.py .
    
    =========================== 3 passed in 0.01 seconds ===========================