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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 _parse_tag(self, el):
 """Extract the namespace and tag from an element."""

        ns = None
        tag = el.tag
        if tag[0] == '{':
            ns, tag = tag[1:].split('}', 1)
            if self.ns_map and ns in self.ns_map:
                ns = self.ns_map[ns]
        return ns, tag