__init__.py 文件源码

def scrub_py2_sys_modules():
    """
    Removes any Python 2 standard library modules from ``sys.modules`` that
    would interfere with Py3-style imports using import hooks. Examples are
    modules with the same names (like urllib or email).

    (Note that currently import hooks are disabled for modules like these
    with ambiguous names anyway ...)
    """
    if PY3:
        return {}
    scrubbed = {}
    for modulename in REPLACED_MODULES & set(RENAMES.keys()):
        if not modulename in sys.modules:
            continue

        module = sys.modules[modulename]

        if is_py2_stdlib_module(module):
            flog.debug('Deleting (Py2) {} from sys.modules'.format(modulename))
            scrubbed[modulename] = sys.modules[modulename]
            del sys.modules[modulename]
    return scrubbed