Serious coders understand that Python is powerful but it's not for everything - you won't make soup with it. It has been said many times over that each language has it's own purpose.
I myself use Python a lot, but it's usually for quick macro scripts, sometimes I write a bigger project in it but only because it's so easy to do it, and Python is very big among scientists - there are a lot of great libs for plotting, serious scientific calculations, data analysis and all that jazz.
As much as I love python I choose other languages over it for different types of projects, such as C/++, Java, Delphi....
However I do agree with vezzy that programmers that learn Python and think it's the absolute bomb, then refuse to learn anything else, are nothing but ignorant fools.
Now talking about ruby, it is being used, but the way I see it, Ruby is more for large projects, some to replace PHP. You don't see a lot of simple, macro ruby scripts... or at least I don't?
Kinda drunk, I dunno...
a programmer must know at least a few languages to get around, that is my point. Python is good, but not for everything.