python正则表达式将字符串切割成单词列表

# -*-coding:utf-8-*-
import re
str='''I like to read novel books.
When I start    to go to primary school,
my parents have bought me a lot of novel books,
because they want me to fall in love with reading.
Indeed, thanks to these books, I feel very excited about studying
the knowledge. The novel books open my vision and
I am good at writing. I want to write a book and read them
to my families and friends.'''
if __name__ == '__main__':
word_list=re.split(r"\b[\.,\s\n\r\n]+?\b",str)
for word in word_list:
print word