Python Regex to extract maximum numeric value from a string

Given an alphanumeric string, extract maximum numeric value from that string. Alphabets will only be in lower case.


Input : 100klh564abc365bg
Output : 564
Maximum numeric value among 100, 564 
and 365 is 564.

Input : abchsd0sdhs
Output : 0

This problem has existing solution please refer Extract maximum numeric value from a given string | Set 1 (General approach) link. We will solve this problem quickly in python using Regex. Approach is very simple,

  1. Find list of all integer numbers in string separated by lower case characters using re.findall(expression,string) method.
  2. Convert each number in form of string into decimal number and then find max of it.




# Function to extract maximum numeric value from 
# a given string
import re
def extractMax(input):
     # get a list of all numbers separated by 
     # lower case characters 
     # \d+ is a regular expression which means
     # one or more digit
     # output will be like ['100','564','365']
     numbers = re.findall('\d+',input)
     # now we need to convert each number into integer
     # int(string) converts string into integer
     # we will map int() function onto all elements 
     # of numbers list
     numbers = map(int,numbers)
     print max(numbers)
# Driver program
if __name__ == "__main__":
    input = '100klh564abc365bg'




Attention reader! Don’t stop learning now. Get hold of all the important DSA concepts with the DSA Self Paced Course at a student-friendly price and become industry ready.

My Personal Notes arrow_drop_up

Experienced Software Engineer with a demonstrated history of working in the information technology and services industry Skilled in Big Data technologies, Data Structures, Algorithm, Software Development, App Development, Databases, Python, Java, C, and WordPress

If you like GeeksforGeeks and would like to contribute, you can also write an article using or mail your article to See your article appearing on the GeeksforGeeks main page and help other Geeks.

Please Improve this article if you find anything incorrect by clicking on the "Improve Article" button below.