After implementing strings, I worked on implementing extractors. I found that Python actually provides several modules for extracting files. For example, with a instantiating an 'tarfile' object, we could extract files that end with .gz, .bz... Therefore, I modified extractor file, that if the system doesn't have processes like 'tar', 'unzip', it will use the python implemented method to extract target. This works for tar and zip, exe... Besides, for rpm and deb, I found that there is a package called libarchive, so I guess maybe we could use it. And in the following days of this week I will start implementing other extractors that python doesn't have a module to solve.
Right now I'm working on extracting cab files. I saw on github people have implemented such extractor in Python, so I will understand their code first and see what I could do (use it, rewrite it in C, etc...)