test_selectors2.py 文件源码

def patch_select_module(testcase, *keep, **replace):
    """ Helper function that removes all selectors from the select module
    except those listed in *keep and **replace. Those in keep will be kept
    if they exist in the select module and those in replace will be patched
    with the value that is given regardless if they exist or not. Cleanup
    will restore previous state. This helper also resets the selectors module
    so that a call to DefaultSelector() will do feature detection again. """

    selectors2._DEFAULT_SELECTOR = None
    for s in ['select', 'poll', 'epoll', 'kqueue']:
        if s in replace:
            if hasattr(select, s):
                old_selector = getattr(select, s)
                testcase.addCleanup(setattr, select, s, old_selector)
            else:
                testcase.addCleanup(delattr, select, s)
            setattr(select, s, replace[s])
        elif s not in keep and hasattr(select, s):
            old_selector = getattr(select, s)
            testcase.addCleanup(setattr, select, s, old_selector)
            delattr(select, s)