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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 _admx_policy_parent_walk(path,
                             policy_namespace,
                             parent_category,
                             policy_nsmap,
                             return_full_policy_names,
                             adml_language):
    '''
    helper function to recursively walk up the ADMX namespaces and build the
    hierarchy for the policy
    '''
    admx_policy_definitions = _get_policy_definitions(language=adml_language)
    category_xpath_string = '/policyDefinitions/categories/{0}:category[@name="{1}"]'
    using_xpath_string = '/policyDefinitions/policyNamespaces/{0}:using'
    if parent_category.find(':') >= 0:
        # the parent is in another namespace
        policy_namespace = parent_category.split(':')[0]
        parent_category = parent_category.split(':')[1]
        using_xpath_string = using_xpath_string.format(policy_namespace)
        policy_nsmap = dictupdate.update(policy_nsmap,
                                         _buildElementNsmap(admx_policy_definitions.xpath(using_xpath_string,
                                                                                          namespaces=policy_nsmap)))
    category_xpath_string = category_xpath_string.format(policy_namespace, parent_category)
    if admx_policy_definitions.xpath(category_xpath_string, namespaces=policy_nsmap):
        tparent_category = admx_policy_definitions.xpath(category_xpath_string,
                                                         namespaces=policy_nsmap)[0]
        this_parent_name = _getFullPolicyName(
            policy_item=tparent_category,
            policy_name=tparent_category.attrib['name'],
            return_full_policy_names=return_full_policy_names,
            adml_language=adml_language)
        path.append(this_parent_name)
        if tparent_category.xpath('{0}:parentCategory/@ref'.format(policy_namespace), namespaces=policy_nsmap):
            # parent has a parent
            path = _admx_policy_parent_walk(
                path=path,
                policy_namespace=policy_namespace,
                parent_category=tparent_category.xpath('{0}:parentCategory/@ref'.format(policy_namespace), namespaces=policy_nsmap)[0],
                policy_nsmap=policy_nsmap,
                return_full_policy_names=return_full_policy_names,
                adml_language=adml_language)
    return path