python 原始字符串
1、原始字符串
raw 字符串
【特点】对字符串中的内容不进行转义(让转义符号 \ 无效),即表达原始含义
e.g:r"\b" ---> \b
"\\b" ---> \b
In [5]: import re
In [6]: re.findall("\\w+@\\w+\\.cn","axs@zhongguo.cn")
Out[6]: ['axs@zhongguo.cn']
In [7]: re.findall(r"\w+@\w+\.cn","axs@zhongguo.cn")
Out[7]: ['axs@zhongguo.cn']
In [9]: s = 'C:\newfile\test.py'
...: print(s)
...: print(len(s))
...: s = r'C:\newfile\test.py'
...: print(s)
...: print(len(s))
C:
ewfile est.py
16
C:\newfile\test.py
18