python练习 让繁琐的工作自动化

#为啥两段代码运行结果不一样？

import re
>>> agentNameRegex = re.compile(r"Agent(\w)\w*")
>>> agentNameRegex.sub(r"\1****","Agent Alice told Agent Carol that Agent Eve knew Agent Bob was a double agent.")

注意正则表达式中的空格：

>>> agentNameRegex = re.compile(r"Agent (\w)\w*")
>>> agentNameRegex.sub(r"\1****","Agent Alice told Agent Carol that Agent Eve knew Agent Bob was a double agent.")

'A**** told C**** that E**** knew B**** was a double agent.'