Hi! I have been working on the python interface to GiNaC. It is quite usable already and I have tested it in many problems. However, it would be great if some python specific changes that I had to do in GiNaC, could be added to GiNaC. These changes include mostly printing expressions. Earlier I used hooks from GiNaC archive features to get desired output for python, but it was _very_ slow compared to the native GiNaC print hooks. So, please find a patch attached that adds two new print_context classes, print_python and print_python_repr, with the corresponding additions to print methods of the basic classes. The patch includes also the following change in the idx::print method for print_latex context: `a.b' becomes `a_{b}' if b is covariant, `a^{b}', otherwise (you can ignore it if you don't like it). This patch is against GiNaC-1.0.1. I can make it also against the latest GiNaC in CVS. Let me know if needed. Thanks, Pearu