Python String isnumeric() and its application

Last Updated : 03 Apr, 2020

In Python, isnumeric() is a built-in method used for string handling. The issnumeric() methods returns “True” if all characters in the string are numeric characters, Otherwise, It returns “False”.
This function is used to check if the argument contains all numeric characters such as : integers, fractions, subscript, superscript, roman numerals etc.(all written in unicode)

Syntax :

string.isnumeric()
Parameters:
isnumeric() does not take any parameters
Returns :
1.True- If all characters in the string are numeric characters.
2.False- If the string contains 1 or more non-numeric characters.

Examples:

Input : string = '1889345'
Output : True

Input : string = '\u00BD'
Output : True

Input : string = '123ayu456'
Output : False

# Python code for implementation of isnumeric()
    
# checking for numeric characters
string = '123ayu456'
print(string.isnumeric())
   
string = '123456'
print( string.isnumeric())

Output:

False
True

Errors and Exceptions

It does not contain any arguments, therefore, it returns an error if a parameter is passed.
Whitespaces are not considered to be numeric, therefore, it returns “False”
Subscript, Superscript, Fractions, Roman numerals (all written in unicode)are all considered to be numeric, Therefore, it returns “True”

Application : Given a string in python, count number of numeric characters in the string and remove them from the string and print the string.
Examples:

Input : string = '123geeks456for789geeks'
Output : 9
         geeksforgeeks

Input : string = '123ayu456'
Output : 6
         ayu

Algorithm
1. Initialise an empty newstring and variable count to 0.
1. Traverse the given string character by character upto its length, check if character is a numeric character.
2. If it is a numeric character, increment the counter by 1 and do not add it to the new string, else traverse to the next character and keep adding the characters to the new string if not numeric.
3. Print the value of the counter and the newstring.

# Python implementation to count numeric characters
# in a string and print non numeric characters
# Given string
# Initialising the counter to 0
string ='123geeks456for789geeks'
count = 0
  
newstring1 =""
newstring2 =""
    
# Iterating the string and checking for numeric characters
# Incrementing the counter if a numeric character is found
# And adding the character to new string if not numeric
# Finally printing the count and the newstring
for a in string:
    if (a.isnumeric()) == True:
        count+= 1
    else:
        newstring1+= a
print(count)
print(newstring1)
   
string ='123ayu456'
count = 0
for a in string:
    if (a.isnumeric()) == True:
        count+= 1
    else:
        newstring2+= a
print(count)
print(newstring2)

Output:

9
geeksforgeeks
6
ayu

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Python String isnumeric() and its application