python re. sub of Replace Regular Matching Content Method

As shown below:

import re
 
 
c = re.compile(r'\d')
 
s = 'you1are2welcome'
 
#  Replaces the contents of the regular match with the specified contents, or you can specify the number of replacements 
ret = c.sub(' ', s, 1)
 
print(ret)
 
 
#  Handler function receive 1 Parameters ( The result of each match )
def deal(s):
  return str(int(s.group()) * 2)
 
#  It can be considered as intervening in the replacement process, passing 1 One function is enough 
ret = re.sub(r'\d', deal, 'you1are2welcome')
print(ret)

Results:

you are2welcome

you2are4welcome