What does the "s!" operator in Perl do?

Question

I have this Perl snippet from a script that I am translating into Python. I have no idea what the "s!" operator is doing; some sort of regex substitution. Unfortunately searching Google or Stackoverflow for operators like that doesn't yield many helpful results.

 $var =~ s!<foo>.+?</foo>!!;
 $var =~ s!;!/!g;

What is each line doing? I'd like to know in case I run into this operator again.

And, what would equivalent statements in Python be?

Answer 1

s!foo!bar! is the same as the more common s/foo/bar/, except that foo and bar can contain unescaped slashes without causing problems. What it does is, it replaces the first occurence of the regex foo with bar. The version with g replaces all occurences.