在正则表达式中使用替换函数，提取数字，将它们转换为整数，然后转换为字符:

Use a replacement function in your regex, which extracts the digits, converts them to integer, and then to character:

import re

s = "He#108##108#o"

print(re.sub("#(\d+)#", lambda x : chr(int(x.group(1))), s))

结果:

Hello