[web2py] oposite to XML operation or how to escape string

[KMax]

Hello
 I have a string with '&&' which must be replaced by <br />
 If I change all && with <br /> and XML it, it could miss other html
tag in a string
 I could join  '<br/ >'.join(DIV(substr)), but I do not need div tag
in output.

 So how to escaped string without DIV or other HTML helper?

 I look at web2py source, but miss that thing.

Thank you.