Data IO, formatting, pre and post processing and presentation.
My standard approach is to use python to read in all my data, parse it, format it and beat it into the shape I want. Then, if I need the performance, I pass the data to a highly tuned C function for slowest number crunching parts. Then I take the data back from C and parse it, format it, summarize it and write it out to the file formats I want using python. C may be faster for number crunching, but python is much nicer for data handling, and there the performance difference is negligible.
My standard approach is to use python to read in all my data, parse it, format it and beat it into the shape I want. Then, if I need the performance, I pass the data to a highly tuned C function for slowest number crunching parts. Then I take the data back from C and parse it, format it, summarize it and write it out to the file formats I want using python. C may be faster for number crunching, but python is much nicer for data handling, and there the performance difference is negligible.