diff --git a/python/chcat/chcat b/python/chcat/chcat
index 68718ec5f102..ec34c05ffdfa 100755
--- a/python/chcat/chcat
+++ b/python/chcat/chcat
@@ -217,7 +217,7 @@ def chcat_remove(orig, newcat, objects, login_ind):
             else:
                 cat = ""
         else:
-            print(_("%s is not in %s") % (f, orig))
+            print(_("{target} is not in {category}").format(target=f, category=orig))
             continue
 
         if len(cat) == 0:
diff --git a/python/semanage/seobject.py b/python/semanage/seobject.py
index d82da4942987..8a891ca23bca 100644
--- a/python/semanage/seobject.py
+++ b/python/semanage/seobject.py
@@ -1175,13 +1175,13 @@ class portRecords(semanageRecords):
 
         (rc, exists) = semanage_port_exists(self.sh, k)
         if rc < 0:
-            raise ValueError(_("Could not check if port %s/%s is defined") % (proto, port))
+            raise ValueError(_("Could not check if port {proto}/{port} is defined").format(proto=proto, port=port))
         if not exists:
-            raise ValueError(_("Port %s/%s is not defined") % (proto, port))
+            raise ValueError(_("Port {proto}/{port} is not defined").format(proto=proto, port=port))
 
         (rc, p) = semanage_port_query(self.sh, k)
         if rc < 0:
-            raise ValueError(_("Could not query port %s/%s") % (proto, port))
+            raise ValueError(_("Could not query port {proto}/{port}").format(proto=proto, port=port))
 
         con = semanage_port_get_con(p)
 
@@ -1195,7 +1195,7 @@ class portRecords(semanageRecords):
 
         rc = semanage_port_modify_local(self.sh, k, p)
         if rc < 0:
-            raise ValueError(_("Could not modify port %s/%s") % (proto, port))
+            raise ValueError(_("Could not modify port {proto}/{port}").format(proto=proto, port=port))
 
         semanage_port_key_free(k)
         semanage_port_free(p)
@@ -1241,19 +1241,19 @@ class portRecords(semanageRecords):
         (k, proto_d, low, high) = self.__genkey(port, proto)
         (rc, exists) = semanage_port_exists(self.sh, k)
         if rc < 0:
-            raise ValueError(_("Could not check if port %s/%s is defined") % (proto, port))
+            raise ValueError(_("Could not check if port {proto}/{port} is defined").format(proto=proto, port=port))
         if not exists:
-            raise ValueError(_("Port %s/%s is not defined") % (proto, port))
+            raise ValueError(_("Port {proto}/{port} is not defined").format(proto=proto, port=port))
 
         (rc, exists) = semanage_port_exists_local(self.sh, k)
         if rc < 0:
-            raise ValueError(_("Could not check if port %s/%s is defined") % (proto, port))
+            raise ValueError(_("Could not check if port {proto}/{port} is defined").format(proto=proto, port=port))
         if not exists:
-            raise ValueError(_("Port %s/%s is defined in policy, cannot be deleted") % (proto, port))
+            raise ValueError(_("Port {proto}/{port} is defined in policy, cannot be deleted").format(proto=proto, port=port))
 
         rc = semanage_port_del_local(self.sh, k)
         if rc < 0:
-            raise ValueError(_("Could not delete port %s/%s") % (proto, port))
+            raise ValueError(_("Could not delete port {proto}/{port}").format(proto=proto, port=port))
 
         semanage_port_key_free(k)
 
@@ -1362,7 +1362,7 @@ class ibpkeyRecords(semanageRecords):
 
         (rc, k) = semanage_ibpkey_key_create(self.sh, subnet_prefix, low, high)
         if rc < 0:
-            raise ValueError(_("Could not create a key for %s/%s") % (subnet_prefix, pkey))
+            raise ValueError(_("Could not create a key for {subnet_prefix}/{pkey}").format(subnet_prefix=subnet_prefix, pkey=pkey))
         return (k, subnet_prefix, low, high)
 
     def __add(self, pkey, subnet_prefix, serange, type):
@@ -1384,44 +1384,44 @@ class ibpkeyRecords(semanageRecords):
 
         (rc, exists) = semanage_ibpkey_exists(self.sh, k)
         if rc < 0:
-            raise ValueError(_("Could not check if ibpkey %s/%s is defined") % (subnet_prefix, pkey))
+            raise ValueError(_("Could not check if ibpkey {subnet_prefix}/{pkey} is defined").formnat(subnet_prefix=subnet_prefix, pkey=pkey))
         if exists:
-            raise ValueError(_("ibpkey %s/%s already defined") % (subnet_prefix, pkey))
+            raise ValueError(_("ibpkey {subnet_prefix}/{pkey} already defined").format(subnet_prefix=subnet_prefix, pkey=pkey))
 
         (rc, p) = semanage_ibpkey_create(self.sh)
         if rc < 0:
-            raise ValueError(_("Could not create ibpkey for %s/%s") % (subnet_prefix, pkey))
+            raise ValueError(_("Could not create ibpkey for {subnet_prefix}/{pkey}").format(subnet_prefix=subnet_prefix, pkey=pkey))
 
         semanage_ibpkey_set_subnet_prefix(self.sh, p, subnet_prefix)
         semanage_ibpkey_set_range(p, low, high)
         (rc, con) = semanage_context_create(self.sh)
         if rc < 0:
-            raise ValueError(_("Could not create context for %s/%s") % (subnet_prefix, pkey))
+            raise ValueError(_("Could not create context for {subnet_prefix}/{pkey}").format(subnet_prefix=subnet_prefix, pkey=pkey))
 
         rc = semanage_context_set_user(self.sh, con, "system_u")
         if rc < 0:
-            raise ValueError(_("Could not set user in ibpkey context for %s/%s") % (subnet_prefix, pkey))
+            raise ValueError(_("Could not set user in ibpkey context for {subnet_prefix}/{pkey}").format(subnet_prefix=subnet_prefix, pkey=pkey))
 
         rc = semanage_context_set_role(self.sh, con, "object_r")
         if rc < 0:
-            raise ValueError(_("Could not set role in ibpkey context for %s/%s") % (subnet_prefix, pkey))
+            raise ValueError(_("Could not set role in ibpkey context for {subnet_prefix}/{pkey}").format(subnet_prefix=subnet_prefix, pkey=pkey))
 
         rc = semanage_context_set_type(self.sh, con, type)
         if rc < 0:
-            raise ValueError(_("Could not set type in ibpkey context for %s/%s") % (subnet_prefix, pkey))
+            raise ValueError(_("Could not set type in ibpkey context for {subnet_prefix}/{pkey}").format(subnet_prefix=subnet_prefix, pkey=pkey))
 
         if (is_mls_enabled == 1) and (serange != ""):
             rc = semanage_context_set_mls(self.sh, con, serange)
             if rc < 0:
-                raise ValueError(_("Could not set mls fields in ibpkey context for %s/%s") % (subnet_prefix, pkey))
+                raise ValueError(_("Could not set mls fields in ibpkey context for {subnet_prefix}/{pkey}").format(subnet_prefix=subnet_prefix, pkey=pkey))
 
         rc = semanage_ibpkey_set_con(self.sh, p, con)
         if rc < 0:
-            raise ValueError(_("Could not set ibpkey context for %s/%s") % (subnet_prefix, pkey))
+            raise ValueError(_("Could not set ibpkey context for {subnet_prefix}/{pkey}").format(subnet_prefix=subnet_prefix, pkey=pkey))
 
         rc = semanage_ibpkey_modify_local(self.sh, k, p)
         if rc < 0:
-            raise ValueError(_("Could not add ibpkey %s/%s") % (subnet_prefix, pkey))
+            raise ValueError(_("Could not add ibpkey {subnet_prefix}/{pkey}").format(subnet_prefix=subnet_prefix, pkey=pkey))
 
         semanage_context_free(con)
         semanage_ibpkey_key_free(k)
@@ -1448,13 +1448,13 @@ class ibpkeyRecords(semanageRecords):
 
         (rc, exists) = semanage_ibpkey_exists(self.sh, k)
         if rc < 0:
-            raise ValueError(_("Could not check if ibpkey %s/%s is defined") % (subnet_prefix, pkey))
+            raise ValueError(_("Could not check if ibpkey {subnet_prefix}/{pkey} is defined").format(subnet_prefix=subnet_prefix, pkey=pkey))
         if not exists:
-            raise ValueError(_("ibpkey %s/%s is not defined") % (subnet_prefix, pkey))
+            raise ValueError(_("ibpkey {subnet_prefix}/{pkey} is not defined").format(subnet_prefix=subnet_prefix, pkey=pkey))
 
         (rc, p) = semanage_ibpkey_query(self.sh, k)
         if rc < 0:
-            raise ValueError(_("Could not query ibpkey %s/%s") % (subnet_prefix, pkey))
+            raise ValueError(_("Could not query ibpkey {subnet_prefix}/{pkey}").format(subnet_prefix=subnet_prefix, pkey=pkey))
 
         con = semanage_ibpkey_get_con(p)
 
@@ -1508,13 +1508,13 @@ class ibpkeyRecords(semanageRecords):
 
         (rc, exists) = semanage_ibpkey_exists_local(self.sh, k)
         if rc < 0:
-            raise ValueError(_("Could not check if ibpkey %s/%s is defined") % (subnet_prefix, pkey))
+            raise ValueError(_("Could not check if ibpkey {subnet_prefix}/{pkey} is defined").format(subnet_prefix=subnet_prefix, pkey=pkey))
         if not exists:
-            raise ValueError(_("ibpkey %s/%s is defined in policy, cannot be deleted") % (subnet_prefix, pkey))
+            raise ValueError(_("ibpkey {subnet_prefix}/{pkey} is defined in policy, cannot be deleted").format(subnet_prefix=subnet_prefix, pkey=pkey))
 
         rc = semanage_ibpkey_del_local(self.sh, k)
         if rc < 0:
-            raise ValueError(_("Could not delete ibpkey %s/%s") % (subnet_prefix, pkey))
+            raise ValueError(_("Could not delete ibpkey {subnet_prefix}/{pkey}").format(subnet_prefix=subnet_prefix, pkey=pkey))
 
         semanage_ibpkey_key_free(k)
 
@@ -1617,7 +1617,7 @@ class ibendportRecords(semanageRecords):
 
         (rc, k) = semanage_ibendport_key_create(self.sh, ibdev_name, port)
         if rc < 0:
-            raise ValueError(_("Could not create a key for ibendport %s/%s") % (ibdev_name, ibendport))
+            raise ValueError(_("Could not create a key for ibendport {ibdev_name}/{ibendport}").format(ibdev_name=ibdev_name, ibendport=ibendport))
         return (k, ibdev_name, port)
 
     def __add(self, ibendport, ibdev_name, serange, type):
@@ -1638,9 +1638,9 @@ class ibendportRecords(semanageRecords):
 
         (rc, exists) = semanage_ibendport_exists(self.sh, k)
         if rc < 0:
-            raise ValueError(_("Could not check if ibendport %s/%s is defined") % (ibdev_name, port))
+            raise ValueError(_("Could not check if ibendport {ibdev_name}/{port} is defined").format(ibdev_name=ibdev_name, port=port))
         if exists:
-            raise ValueError(_("ibendport %s/%s already defined") % (ibdev_name, port))
+            raise ValueError(_("ibendport {ibdev_name}/{port} already defined").format(ibdev_name=ibdev_name, port=port))
 
         (rc, p) = semanage_ibendport_create(self.sh)
         if rc < 0:
@@ -1650,32 +1650,32 @@ class ibendportRecords(semanageRecords):
         semanage_ibendport_set_port(p, port)
         (rc, con) = semanage_context_create(self.sh)
         if rc < 0:
-            raise ValueError(_("Could not create context for %s/%s") % (ibdev_name, port))
+            raise ValueError(_("Could not create context for {ibendport}/{port}").format(ibdev_name=ibdev_name, port=port))
 
         rc = semanage_context_set_user(self.sh, con, "system_u")
         if rc < 0:
-            raise ValueError(_("Could not set user in ibendport context for %s/%s") % (ibdev_name, port))
+            raise ValueError(_("Could not set user in ibendport context for {ibdev_name}/{port}").format(ibdev_name=ibdev_name, port=port))
 
         rc = semanage_context_set_role(self.sh, con, "object_r")
         if rc < 0:
-            raise ValueError(_("Could not set role in ibendport context for %s/%s") % (ibdev_name, port))
+            raise ValueError(_("Could not set role in ibendport context for {ibdev_name}/{port}").format(ibdev_name=ibdev_name, port=port))
 
         rc = semanage_context_set_type(self.sh, con, type)
         if rc < 0:
-            raise ValueError(_("Could not set type in ibendport context for %s/%s") % (ibdev_name, port))
+            raise ValueError(_("Could not set type in ibendport context for {ibdev_name}/{port}").format(ibdev_name=ibdev_name, port=port))
 
         if (is_mls_enabled == 1) and (serange != ""):
             rc = semanage_context_set_mls(self.sh, con, serange)
             if rc < 0:
-                raise ValueError(_("Could not set mls fields in ibendport context for %s/%s") % (ibdev_name, port))
+                raise ValueError(_("Could not set mls fields in ibendport context for {ibdev_name}/{port}").format(ibdev_name=ibdev_name, port=port))
 
         rc = semanage_ibendport_set_con(self.sh, p, con)
         if rc < 0:
-            raise ValueError(_("Could not set ibendport context for %s/%s") % (ibdev_name, port))
+            raise ValueError(_("Could not set ibendport context for {ibdev_name}/{port}").format(ibdev_name=ibdev_name, port=port))
 
         rc = semanage_ibendport_modify_local(self.sh, k, p)
         if rc < 0:
-            raise ValueError(_("Could not add ibendport %s/%s") % (ibdev_name, port))
+            raise ValueError(_("Could not add ibendport {ibdev_name}/{port}").format(ibdev_name=ibdev_name, port=port))
 
         semanage_context_free(con)
         semanage_ibendport_key_free(k)
@@ -1702,9 +1702,9 @@ class ibendportRecords(semanageRecords):
 
         (rc, exists) = semanage_ibendport_exists(self.sh, k)
         if rc < 0:
-            raise ValueError(_("Could not check if ibendport %s/%s is defined") % (ibdev_name, ibendport))
+            raise ValueError(_("Could not check if ibendport {ibdev_name}/{ibendport} is defined").format(ibdev_name=ibdev_name, ibendport=ibendport))
         if not exists:
-            raise ValueError(_("ibendport %s/%s is not defined") % (ibdev_name, ibendport))
+            raise ValueError(_("ibendport {ibdev_name}/{ibendport} is not defined").format(ibdev_name=ibdev_name, ibendport=ibendport))
 
         (rc, p) = semanage_ibendport_query(self.sh, k)
         if rc < 0:
@@ -1719,7 +1719,7 @@ class ibendportRecords(semanageRecords):
 
         rc = semanage_ibendport_modify_local(self.sh, k, p)
         if rc < 0:
-            raise ValueError(_("Could not modify ibendport %s/%s") % (ibdev_name, ibendport))
+            raise ValueError(_("Could not modify ibendport {ibdev_name}/{ibendport}").format(ibdev_name=ibdev_name, ibendport=ibendport))
 
         semanage_ibendport_key_free(k)
         semanage_ibendport_free(p)
@@ -1741,11 +1741,11 @@ class ibendportRecords(semanageRecords):
             port = semanage_ibendport_get_port(ibendport)
             (k, ibdev_name, port) = self.__genkey(str(port), ibdev_name)
             if rc < 0:
-                raise ValueError(_("Could not create a key for %s/%d") % (ibdevname, port))
+                raise ValueError(_("Could not create a key for {ibdev_name}/{port}").format(ibdev_name=ibdev_name, port=port))
 
             rc = semanage_ibendport_del_local(self.sh, k)
             if rc < 0:
-                raise ValueError(_("Could not delete the ibendport %s/%d") % (ibdev_name, port))
+                raise ValueError(_("Could not delete the ibendport {ibdev_name}/{port}").format(ibdev_name=ibdev_name, port=port))
             semanage_ibendport_key_free(k)
 
         self.commit()
@@ -1754,19 +1754,19 @@ class ibendportRecords(semanageRecords):
         (k, ibdev_name, port) = self.__genkey(ibendport, ibdev_name)
         (rc, exists) = semanage_ibendport_exists(self.sh, k)
         if rc < 0:
-            raise ValueError(_("Could not check if ibendport %s/%s is defined") % (ibdev_name, ibendport))
+            raise ValueError(_("Could not check if ibendport {ibdev_name}/{ibendport} is defined").format(ibdev_name=ibdev_name, ibendport=ibendport))
         if not exists:
-            raise ValueError(_("ibendport %s/%s is not defined") % (ibdev_name, ibendport))
+            raise ValueError(_("ibendport {ibdev_name}/{ibendport} is not defined").format(ibdev_name=ibdev_name, ibendport=ibendport))
 
         (rc, exists) = semanage_ibendport_exists_local(self.sh, k)
         if rc < 0:
-            raise ValueError(_("Could not check if ibendport %s/%s is defined") % (ibdev_name, ibendport))
+            raise ValueError(_("Could not check if ibendport {ibdev_name}/{ibendport} is defined").format(ibdev_name=ibdev_name, ibendport=ibendport))
         if not exists:
-            raise ValueError(_("ibendport %s/%s is defined in policy, cannot be deleted") % (ibdev_name, ibendport))
+            raise ValueError(_("ibendport {ibdev_name}/{ibendport} is defined in policy, cannot be deleted").format(ibdev_name=ibdev_name, ibendport=ibendport))
 
         rc = semanage_ibendport_del_local(self.sh, k)
         if rc < 0:
-            raise ValueError(_("Could not delete ibendport %s/%s") % (ibdev_name, ibendport))
+            raise ValueError(_("Could not delete ibendport {ibdev_name}/{ibendport}").format(ibdev_name=ibdev_name, ibendport=ibendport))
 
         semanage_ibendport_key_free(k)
 
