How do you determine if an IP address is private, in Python?

Question

In Python, what is the best way to determine if an IP address (e.g., \'127.0.0.1\' or \'10.98.76.6\') is on a private network? The code does not s

Answer 1

This is the fixed version of the regex approach suggested by @Kurt including the fix recommended by @RobEvans

• ^127.\d{1,3}.\d{1,3}.\d{1,3}$
• ^10.\d{1,3}.\d{1,3}.\d{1,3}$
• ^192.168.\d{1,3}.\d{1,3}$

• ^172.(1[6-9]|2[0-9]|3[0-1]).[0-9]{1,3}.[0-9]{1,3}$

  def is_ip_private(ip):
  
      # https://en.wikipedia.org/wiki/Private_network
  
      priv_lo = re.compile("^127\.\d{1,3}\.\d{1,3}\.\d{1,3}$")
      priv_24 = re.compile("^10\.\d{1,3}\.\d{1,3}\.\d{1,3}$")
      priv_20 = re.compile("^192\.168\.\d{1,3}.\d{1,3}$")
      priv_16 = re.compile("^172.(1[6-9]|2[0-9]|3[0-1]).[0-9]{1,3}.[0-9]{1,3}$")
  
      res = priv_lo.match(ip) or priv_24.match(ip) or priv_20.match(ip) or priv_16.match(ip)
      return res is not None