I have some old apps written in PHP that I'm thinking of converting to Python - both are websites that started as simple static html, then progressed to PHP and now include blogs with admin areas, rss etc. I'm thinking of rewriting them in Python to improve maintainability as well as to take advantage of my increase in experience to write things more robustly.
Is this worth the effort?
If you are going to add more features to the code you already have working, then it might be a good idea to port it to python. After all, it will get you increased productivity. You just have to balance it, whether the rewriting task will not outweigh the potential gain... 
And also, when you do that, try to unittest as much as you can.
Is rewriting a PHP app into Python a productive step?