python - Python:正则表达式和字符串长度(以字节为单位)

我正在用python编写程序，并且有一些问题（我是python的100％新手）：

import re

rawData = '7I+8I-7I-9I-8I-'

print len(rawData)

rawData = re.sub("[0-9]I\+","",rawData)
rawData = re.sub("[0-9]I\-","",rawData)

print rawData

如何使用|将2个正则表达式合并为一个？这意味着仅使用一个正则表达式操作就可以同时消除9I-和9I+。
len（rawData）是否返回rawData的长度为字节？


谢谢。

最佳答案

看到不同：

$ python3
Python 3.1.3 (r313:86834, May 20 2011, 06:10:42)
[GCC 4.4.5] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> len('día')   # Unicode text
3
>>>

$ python
Python 2.7.1 (r271:86832, May 20 2011, 17:19:04)
[GCC 4.4.5] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> len('día')   # bytes
4
>>> len(u'día')  # Unicode text
3
>>>


Python 3.1.3 (r313:86834, May 20 2011, 06:10:42)
[GCC 4.4.5] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> len(b'día')
  File "<stdin>", line 1
SyntaxError: bytes can only contain ASCII literal characters.
>>> len(b'dia')
3
>>>