That is not how you define a regular expressions in Python. The correct way would be:
import re
lanip="74.125.224.72"
notorm=re.search("([1-9])\w+$", lanip)
print notorm
Output:
<_sre.SRE_Match object at 0x10131df30>
You were using a javascript regex style. To read more on correct python syntax read the documentation
If you want to match the last number of an IP use:
import re
lanip="74.125.224.72"
notorm=re.search("(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)", lanip)
print notorm.group(4)
Output:
72
Regex used from http://www.regular-expressions.info/examples.html
Your example did work in this scenario, but would match a lot of false positives.