diff --git a/python/netlink/core.py b/python/netlink/core.py
index ea78691..b6cf7e9 100644
--- a/python/netlink/core.py
+++ b/python/netlink/core.py
@@ -92,14 +92,14 @@ class NetlinkError(Exception):
 
 class KernelError(NetlinkError):
 	def __str__(self):
-        	return "Kernel returned: " + self._msg
+        	return "Kernel returned: {0}".format(self._msg)
 
 class ImmutableError(NetlinkError):
 	def __init__(self, msg):
         	self._msg = msg
 
 	def __str__(self):
-        	return "Immutable attribute: " + self._msg
+        	return "Immutable attribute: {0}".format(self._msg)
 
 class Message(object):
 	"""Netlink message"""
@@ -162,7 +162,7 @@ class Socket(object):
         	capi.nl_socket_free(self._sock)
 
 	def __str__(self):
-        	return "nlsock<" + str(self.localPort) + ">"
+        	return "nlsock<{0}>".format(self.localPort)
 
 	@property
         def local_port(self):
@@ -626,7 +626,7 @@ class AddressFamily(object):
         	return self._family
 
 	def __repr__(self):
-        	return 'AddressFamily(\'' + str(self) + '\')'
+        	return 'AddressFamily({0!r})'.format(str(self))
 
 
 ###########################################################################
diff --git a/python/netlink/route/link.py b/python/netlink/route/link.py
index 74ec2f9..8c87971 100644
--- a/python/netlink/route/link.py
+++ b/python/netlink/route/link.py
@@ -127,7 +127,7 @@ class LinkCache(netlink.Cache):
 	def __getitem__(self, key):
         	if type(key) is int:
                         link = capi.rtnl_link_get(self._nl_cache, key)
-                elif type(key) is str:
+                else:
                         link = capi.rtnl_link_get_by_name(self._nl_cache, key)
 
 		if link is None:
@@ -227,7 +227,7 @@ class Link(netlink.Object):
 
 	@flags.setter
         def flags(self, value):
-        	if type(value) is list:
+        	if not (type(value) is str):
                         for flag in value:
                                 self._set_flag(flag)
                 else:
diff --git a/python/netlink/route/links/inet.py b/python/netlink/route/links/inet.py
index 76a9e92..b5b1152 100644
--- a/python/netlink/route/links/inet.py
+++ b/python/netlink/route/links/inet.py
@@ -52,7 +52,7 @@ class InetLink(object):
         	self._link = link
 
 	def details(self, fmt):
-		buf = '\n' + fmt.nl('\t%s\n\t' % util.title('Configuration:'))
+		buf = fmt.nl('\n\t{0}\n\t'.format(util.title('Configuration:')))
 
 		for i in range(DEVCONF_FORWARDING,DEVCONF_MAX+1):
 			if i & 1 and i > 1:
diff --git a/python/netlink/route/links/vlan.py b/python/netlink/route/links/vlan.py
index 134e721..c9fe2a7 100644
--- a/python/netlink/route/links/vlan.py
+++ b/python/netlink/route/links/vlan.py
@@ -57,7 +57,7 @@ class VLANLink(object):
 	#   - egress map
 
 	def brief(self):
-		return 'vlan-id ' + self.id
+		return 'vlan-id {0}'.format(self.id)
 
 def init(link):
 	link.vlan = VLANLink(link._link)
diff --git a/python/netlink/util.py b/python/netlink/util.py
index a8c831f..f6e7dec 100644
--- a/python/netlink/util.py
+++ b/python/netlink/util.py
@@ -17,7 +17,7 @@ from string import Formatter
 __version__ = "1.0"
 
 def _color(t, c):
-	return chr(0x1b)+"["+str(c)+"m"+str(t)+chr(0x1b)+"[0m"
+	return b'{esc}[{color}m{text}{esc}[0m'.format(esc=b'\x1b', color=c, text=t)
 
 def black(t):
 	return _color(t, 30)
@@ -126,7 +126,7 @@ class MyFormatter(Formatter):
                 if include_title:
                         if not title:
                                 title = key	# fall back to key as title
-                        value = kw(title) + ' ' + value
+                        value = '{0} {1}'.format(kw(title), value)
 
                 return value