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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 get_subnet_nwk_excl(self, tenant_id, excl_list, excl_part=False):
 """Retrieve the subnets of a network. Get the subnets inside a network after applying the exclusion list. """

        net_list = self.get_network_by_tenant(tenant_id)
        ret_subnet_list = []
        for net in net_list:
            if excl_part:
                name = net.get('name')
                part = name.partition('::')[2]
                if part:
                    continue
            subnet_lst = self.get_subnets_for_net(net.get('id'))
            for subnet_elem in subnet_lst:
                subnet = subnet_elem.get('cidr').split('/')[0]
                subnet_and_mask = subnet_elem.get('cidr')
                if subnet not in excl_list:
                    ret_subnet_list.append(subnet_and_mask)
        return ret_subnet_list