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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 disqus_sso_script(context):
 """ Provides a generic context variable which adds single-sign-on support to DISQUS if ``COMMENTS_DISQUS_API_PUBLIC_KEY`` and ``COMMENTS_DISQUS_API_SECRET_KEY`` are specified. """

    settings = context["settings"]
    public_key = getattr(settings, "COMMENTS_DISQUS_API_PUBLIC_KEY", "")
    secret_key = getattr(settings, "COMMENTS_DISQUS_API_SECRET_KEY", "")
    user = context["request"].user
    if public_key and secret_key and user.is_authenticated():
        context["public_key"] = public_key
        context["sso_data"] = _get_disqus_sso(user, public_key, secret_key)
    return context