Emacs Python-mode. Newbie problem.

[Lacrima]

Hello!

I have just started using Emacs to write python scripts.
I installed python-mode.el

Then I just tried this code:

print 'hello world'

When I press C-c RET, new blank window is opened and emacs says:
(Shell command succeeded with no output)
So where is my 'hello world'?

When I do C-c C-c, it prints 'hello world' successfully.
Why in the first case I get no output?

Thanks in advance!

With regards, Max
(sorry if my English isn't very proper)