Replace Non Alphanumeric Characters in Python

Non-alphanumeric characters in python string can be replaced using python regex module `re`

sub method in re module can be used to replace the non-alphanumeric characters.

Regular expression to exclude the alphanumeric string to be substituted is '[^0-9a-zA-Z]+'.

It can be better explained with an example.

Example

Let’s say, we want to replace non-alphanumeric characters in the string wh!leTru-.l!v-.

import re

host = 'wh!leTru-.l!v-'
non_alphanumeric_host = re.sub('[^0-9a-zA-Z]+', '_', host) 

print(non_alphanumeric_host) # 'wh_leTru_l_v_'