Python | Remove all characters except letters and numbers

Python Methods and Functions | Regular Expressions

String manipulation — a very important task in day to day programming and web development. Most of the requests and responses in HTTP requests are presented as strings with sometimes useless data that we need to delete. Let's discuss some Pythonic ways to remove all characters except numbers and alphabets.

Method # 1: Using re.sub

# Python code for demos
# remove all characters
# except numbers and alphabets

 

import re

 
# initialization string

ini_string = " 123abcjw :,. @! eiw "

 
# print the original line  

print ( "initial string:" , ini_string)

 
# function for demonstrations of removing characters
# which are not numbers and alphabets using re

 

result = re.sub ( '[W _] +' , '', ini_string)

  
# print the final line

print ( "final string" , result)

Exit:

 initial string: 123abcjw :,. @! eiw final string 123abcjweiw 

Method # 2: Using isnumeric ()

# Python code for demonstration
# remove all characters
# except numbers and alphabets

 

import re

 
# initializing string

ini_string = "123abcjw :,. @! eiw "

  
# print the original line

print ( " initial string: " , ini_string)

  
# function to demonstrate removal of characters
# which are not numbers and alphabets using re

getVals = list ( [val for val in ini_string

  if val .isalpha () or val.isnumeric ()])

 

result = " ". join (getVals)

  
# print the final line

print ( "final string" , result)

Exit:

 initial string: 123abcjw :,. @! eiw final string 123abcjweiw 

Method # 3: Using isalnum/ rel=noopener target=_blank> alnum ()

# Python code for demo
# remove all characters
# except numbers and alphabets

 
# initializing string

ini_string = "123abcjw :,. @! eiw"

 
# print the original line

print ( "initial string:" , ini_string)

  
# function to demonstrate removal of characters
# which are not numbers and alphabets using re

getVals = list ([val for val in ini_string if val.isalnum ()])

result = "". join (getVals)

 
# print the final line

print ( "final string" , result )

Exit:

 initial string : 123abc jw :,. @! eiw final string 123abcjweiw 




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