The How to think like a computer scientist book (Python Version).

The goal of this book ... is to teach you to think like a computer scientist. This way of thinking combines some of the best features of Mathematics, Engineering, and Natural Science. Like mathematicians, computer scientists use formal languages to denote ideas (specifically computations). Like engineers, they design things, assembling components into systems and evaluating tradeoffs among alternatives. Like scientists, they observe the behavior of complex systems, form hypotheses, and test predictions.

Another introductory programming text that uses Python is Learning to program and is, according to the author, a wee bit more comprehensive than How to think like a computer scientist.