re.DOTALL

  Below, I use [\s\S] to match each and every character.
  I can't seem to get the same effect using "re.DOTALL"!

  Yet the Python Library Reference says,

|(Dot.) In the default mode, this matches any character except
|a newline. If the DOTALL flag has been specified, this
|matches any character including a newline.
what the Python Library Reference says.

  main.py

import re

text = '''
alpha
<hr>
gamma
<hr>
epsilon
'''[ 1: -1 ]

pattern = r'^.*?\n<hr.*?\n(.*)\n<hr.*$'

output = re.sub( pattern.replace( r'.', r'[\s\S]' ), r'\1', text )
print( output )

print( '--' )

output = re.sub( pattern, r'\1', text, re.DOTALL )
print( output )

  stdout

gamma
--
alpha
<hr>
gamma
<hr>
epsilon