Regular Expressions

[Ron]

This is probably a repeated question, but try as I might I was unable
to find something similar in the archives.

I'm trying to develop a regular expression for recognizing a simplified
C-Style string syntax. I need it to be able to handle escape sequences
of the form \x where x is any character including ".

Here's what I'm trying:

\"([^"\\]|(\\.))*\"

When I try to get it to recognize something like:

"I said, \"Hello!\""

It stops at the first quote after the \.

I've used this very same regular expression in a parser generator I
have for C++ and it works just fine.

Any thoughts on what I'm doing wrong in the Python Reg Ex world?

Thanks for the comments & help.

Ron

 

[MyHaz]

escape chars are always a pain when making regex's. There is a section
on it the Regex HOWTO

http://www.amk.ca/python/howto/regex/regex.html#SECTION000420000000000000000

 

[Roel Schroeven]

This is probably a repeated question, but try as I might I was unable
to find something similar in the archives.

I'm trying to develop a regular expression for recognizing a simplified
C-Style string syntax. I need it to be able to handle escape sequences
of the form \x where x is any character including ".

Here's what I'm trying:

\"([^"\\]|(\\.))*\"

When I try to get it to recognize something like:

"I said, \"Hello!\""

It stops at the first quote after the \.

Works for me:

>>> print re.search(r'\"([^"\\]|(\\.))*\"',

.... r'"I said \"Hello!\""').group(0)
"I said \"Hello!\""


You can leave out the backslashes in fron of the first and last quotes
in the regex, by the way, at least if you use ' instead of " to delimite it:

print re.search(r'"([^"\\]|(\\.))*"',

.... r'"I said \"Hello!\""').group(0)
"I said \"Hello!\""