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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 dict_key_tag(Class, key, namespaces=None):

 """convert a dict key into an element or attribute name"""

        namespaces = namespaces or Class.NS
        ns = Class.tag_namespace(key)
        tag = Class.tag_name(key)
        if ns is None and ':' in key:
            prefix, tag = key.split(':')
            if prefix in namespaces.keys():
                ns = namespaces[prefix]
        if ns is not None:
            tag = "{%s}%s" % (ns, tag)
        return tag