To get familiar with Python, please follow Dive into Python, Chapters 2 through 6. You can download the PDF version, or follow it online.
Of course, depending on your experience with Python, you can skip parts or the entire tutorial. However, if you are not already very familiar with using python, we believe that this tutorial will be very useful.
If you never used the Python interpreter before, this page explains how it works. You run the interpreter by just entering
python
on the command line.
When running the programs in the tutorial, try writing/editing them in Emacs, and run them from the command line:
python my_test_program.py
How long the tutorial will take depends on how familiar you are with Python.
If Dive into Python feels overwhelming and you really need to brush your basic programming concepts, you can follow Learn Python The Hard Way (or alternatively The Python Tutorial). You will go through the basic concepts like loops, if conditions, etc., but it is a much longer process.
If you are very confident about your programming skills and code almost daily, but never really coded in Python, and want to know how to tackle specific coding scenarios in Python, you can look into further chapters in Dive into Python, or use the free online resources listed here.