how to use a variable in python regex code example

Example 1: variable in regex python

import re
s = 'I love books'
var_name = 'love'
result = re.search('(.+)'+var_name+'(.+)',s)
print result
var_name = 'hate'
s2 = 'I hate books'
result = re.search('(.+)'+var_name+'(.+)',s2)
print result

Example 2: re.search variable

if re.search(rf"\b(?=\w){TEXTO}\b(?!\w)", subject, re.IGNORECASE):
    ...do something