You can find the other articles in this serie from the first one: PyKCS11 introduction.
PKCS#11 (Cryptographic Token Interface Standard) is an API used to talk to cryptographic tokens like smart cards (but not only).
The PKCS#11 API is in C language but a wrapper for Python call pykcs11 also exists. We will use this wrapper. The project has a ohloh page.
The wrapper uses SWIG.
"SWIG is an interface compiler that connects programs written in C and C++ with scripting languages such as Perl, Python, Ruby, and Tcl. It works by taking the declarations found in C/C++ header files and using them to generate the wrapper code that scripting languages need to access the underlying C/C++ code. In addition, SWIG provides a variety of customization features that let you tailor the wrapping process to suit your application."
The wrapper is initialy written by Giuseppe Amato (started in 2004). But the API was very low level: one Python function for one PKCS#11 C function. This API was not really Python friendly. When I discovered the project, in 2006, I started writting a higher level API more Python oriented, object oriented and easier to use.
The project is still active. The latest version is 1.2.2 from June 2010.
Since I started this serie on PyKCS I added new methods and improved the wrapper to make it even easier to use.