test_doctest.py 文件源码

def displayhook(): r"""
Test that changing sys.displayhook doesn't matter for doctest.

    >>> import sys
    >>> orig_displayhook = sys.displayhook
    >>> def my_displayhook(x):
    ...     print('hi!')
    >>> sys.displayhook = my_displayhook
    >>> def f():
    ...     '''
    ...     >>> 3
    ...     3
    ...     '''
    >>> test = doctest.DocTestFinder().find(f)[0]
    >>> r = doctest.DocTestRunner(verbose=False).run(test)
    >>> post_displayhook = sys.displayhook

    We need to restore sys.displayhook now, so that we'll be able to test
    results.

    >>> sys.displayhook = orig_displayhook

    Ok, now we can check that everything is ok.

    >>> r
    TestResults(failed=0, attempted=1)
    >>> post_displayhook is my_displayhook
    True
"""