regular expresson for Unix and Dos Lineendings wanted

[Franz Steinhaeusler]

Hello, I need a regularexpression, which trims trailing whitespaces.

While with unix line endings, it works; 
but not with Window (Dos) CRLF's:

>>> import re
>>> retrailingwhitespace = re.compile('(?<=\S)[ \t]+$', re.MULTILINE)

1) Windows
>>> r="erewr    \r\nafjdskl     "
>>> newtext, n = retrailingwhitespace.subn('', r)
>>> n
1
>>> newtext
'erewr    \r\nafjdskl'

2) Unix
>>> r="erewr    \nafjdskl     "
>>> newtext, n = retrailingwhitespace.subn('', r)
>>> n
2
>>> newtext
'erewr\nafjdskl'
>>> 

Who can help me (regular expression, which works for both cases).

Thank you in advance!
-- 
Franz Steinhaeusler