seek()

[Zutroi Zatatakowski]

Is there a kind of seek() function that does the same thing but except
of bytes, it seeks for a string? Basically, I want the 5 next bytes
after a certain string in a file. Example:
Foo:36.50
The data I want (36.50) is located on a web page and since the content
of that page always change, I can't get it with seek() because the bytes
always change too. I've checked in STRING and RE modules but I can't
find a function that checks in a file/webpage, they all need input from
a string. 

-- 
Zutroi Zatatakowski
Commando PACU
http://pacu.cjb.net