I'm looking for something like 'Effective C++' (but for Python of course): a collection of recipes and good practices that would allow an experienced programmer make a better use of the language.
I haven't used any edition of the Python cookbook, but I've used the Perl cookbook and it's just like you described. I have also heard and read that the O'Reilly cookbooks are known (famous even?) for being the kind of books that you described.
If this is a problem, I'll donate all proceeds to the charity of your choice. I'll post images of how much is earned.
Even better - the algorithm you write could go into the 4th edition of the Cookbook :-)
P.S. Everyone should go any buy the book. (I want this comment to count too!)
Seeing it for ~€30, which is ~£25
I can't comment on rails, but I spent quite a long time with django before switching to repoze-bfg (pyramid's previous name). In my experience you don't hit the same wall that you tend to with django when you need to step off the the common path.