比如：
I[空格][空格][空格]LOVE[空格][空格]you！
去除后为：
I[空格]LVOE[空格]you！
" ".join([tk for tk in s.split(" ") if tk])
s = 'I love u forerver !'
result = ' '.join(s.split())
>>> import re
>>> s = "I LOVE YOU"
>>> re.sub(" +", " ", s)
'I LOVE YOU'
正则 /( ){2,}/i->' '