While translating from mel to python is straight forward you might end up doing more than that just because python thinks different.
Mel script tends to tangle gui code, querying maya scene properties and "processing" code, so at least separating them properly is a good first step.
Rewriting the texture manager below using a texture class object shortened the code dramatically.
A 1200 lines melscript is now some 360 lines of python and a .ui file. Python rules...
Here is the code.