The official Python, http://docs.python.org/tutorial/, written by Guido van Rossum himself, is one of the most concise introductions to Python I've read. Just skip the first few chapters.
Dive Into Python is good, but IIRC (from Dive Into Python 2), Mark Pilgrim tends to use very convoluted solutions to simple problems. The solution might be superior in terms of performance, but don't always help you learn the language.
Like K&R, the official docs were written by the language designers/implementors. I think that's important: it eliminates a level of misunderstanding (between the designers and the writers).
Other good books are:
* Learn Python the Hard Way -- http://learnpythonthehardway.org/index
* How to Think Like a Computer Scientist/Think Python (now Python for Software Development) -- http://www.greenteapress.com/thinkpython/
Dive Into Python is good, but IIRC (from Dive Into Python 2), Mark Pilgrim tends to use very convoluted solutions to simple problems. The solution might be superior in terms of performance, but don't always help you learn the language.