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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 _author_uid_get(post):
 """Get the UID of the post author. :param Post post: The post object to determine authorship of :return: Author UID :rtype: str """

    u = post.meta('author.uid')
    return u if u else str(current_user.uid)