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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 is_safe_url(url, host=None):
 """Return ``True`` if the url is a safe redirection. The safe redirection means that it doesn't point to a different host. Always returns ``False`` on an empty url. """

    if not url:
        return False
    netloc = urlparse.urlparse(url)[1]
    return not netloc or netloc == host