Skip to content
Related Articles

Related Articles

Improve Article
Save Article
Like Article

Python | Check if given string is numeric or not

  • Last Updated : 17 May, 2021

Given a string, write a Python program to check if the string is numeric or not. 
Examples: 
 

Input:  28
Output: digit

Input: a
Output: not a digit. 

Input: 21ab
Output: not a digit. 

  
Code #1: Using Python regex 
re.search() : This method either returns None (if the pattern doesn’t match), or a re.MatchObject that contains information about the matching part of the string. This method stops after the first match, so this is best suited for testing a regular expression more than extracting data. 
 

 Attention geek! Strengthen your foundations with the Python Programming Foundation Course and learn the basics.  

To begin with, your interview preparations Enhance your Data Structures concepts with the Python DS Course. And to begin with your Machine Learning Journey, join the Machine Learning - Basic Level Course

Python3




# Python program to identify the Digit
 
# import re module
 
# re module provides support
# for regular expressions
import re
 
# Make a regular expression
# for identifying a digit
regex = '^[0-9]+$'
     
# Define a function for
# identifying a Digit
def check(string):
 
     # pass the regular expression
     # and the string in search() method
    if(re.search(regex, string)):
        print("Digit")
         
    else:
        print("Not a Digit")
     
 
# Driver Code
if __name__ == '__main__' :
     
    # Enter the string
    string = "28"
     
    # calling run function
    check(string)
 
    string = "a"
    check(string)
 
    string = "21ab"
    check(string)
 
    string = "12ab12"
    check(string)
Output: 
Digit
Not a Digit
Not a Digit
Not a Digit

 

  
Code #2: Using string.isnumeric() function 
 

Python3




# Python code to check if string is numeric or not
     
# checking for numeric characters
string = '123ayu456'
print(string.isnumeric())
    
string = '123456'
print(string.isnumeric())
Output: 
False
True

 




My Personal Notes arrow_drop_up
Recommended Articles
Page :

Start Your Coding Journey Now!