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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def seven_zip(archive, items, self_extracting=False):
 """Create a 7z archive."""

    if not isinstance(items, (list, tuple)):
        items = [items]
    if self_extracting:
        return er(_get_sz(), "a", "-ssw", "-sfx", archive, *items)
    else:
        return er(_get_sz(), "a", "-ssw", archive, *items)