请问python中SyntaxError: unexpected character after line continuation character如何解决

import nltk
from nltk.tokenize import RegexpTokenizer
tokenizer=RegexpTokenizer([\w]+"")
**SyntaxError: unexpected character after line continuation character
**

tokenizer=RegexpTokenizer(r"[\w]+")

调用写错了
tokenizer=RegexpTokenizer(r'[\w]+')