Last week I’ve done the ctype wrapper of Glib GString, but the performance issues when compared with cStringIO or StringIO was very poor, due to overhead of the ctypes calls. So I’ve written a new C extension for Python, the source-code (for linux) and install packages (for win32) are available at the project site. Here is some performance comparisons:
Those tests were done to test string concatenation (append) of the three modules. You can find more about the tests and performance in the project site.
I hope you enjoy =)