help with regular expression

[Jason Orendorff]

> I am writing a program in which I need to search an arbitrary string
> and return the part between a certain opening sequence, and a closing
> sequence.  [...]  I want to be able to "escape" the ending
> sequence with either double quotes (">>") or single quotes ('>>').

  r"""<<(('>>'|">>"|>(?!>)|[^>])*)>>"""

See http://www.python.org/doc/current/lib/re-syntax.html
for the meaning of (?!>).

-- 
Jason Orendorff
http://www.jorendorff.com/