+
+
+def convert_ipv4_netmask_prefix(netmask):
+ """Convert network mask to equivalent network prefix length or vice versa.
+
+ Example: mask 255.255.0.0 -> prefix length 16
+ :param netmask: network mask or network prefix length.
+ :type netmask: str or int
+ :return: network mask or network prefix length.
+ :rtype: str or int
+ """
+ temp_address = "0.0.0.0"
+ net = IPv4Network(u"{0}/{1}".format(temp_address, netmask), False)
+
+ if isinstance(netmask, int):
+ return net.netmask
+ elif isinstance(netmask, basestring):
+ return net.prefixlen