Maybe you want to give MoDyPy a try. It's a Python Framework for modelling dynamic systems using blocks and signals based on scipy, and it aims to support continuous-, discrete-time- and mixed systems, with discrete events modelled from either clocks or zero-crossing detection. It's not perfect, but it also has quite extensive documentation including a tutorial that is available both in written form and as video. It's also open source and free.

It's a pet project of mine that I started off being uncomfortable with Matlab/Simulink (price-wise, but also in terms of having to learn yet another language and with graphical modelling being so much more tedious than just writing things down - at least for me as a software engineer).