Before learning Houdini’s Python API, it’s necessary to understand at least a little of the Python language. Fortunately, Python is one of the easiest and most pleasant languages to learn. Teaching you the Python language itself is beyond the scope of the Houdini online help. Luckily, there are many excellent resources available online and in book form.
Python.org also includes the standard library reference. Python has a large set of libraries, or modules, letting you perform a large variety of tasks in Python. This reference is invaluable even after you've learned the core Python language.
Python.org also contains links to other learning resources.
Mark Pilgrim’s Dive into Python book is available in print and free online. This is a very well-written and candid introduction to the language with many small projects to dive into. However, it may be slightly out-of-date with the latest versions of Python.
Many other introductory books are available for Python, such as O'Reilly’s Learning Python.