File type associations

I wanted to associate a program to open a .py file for editing, and to give it an icon. I don't see it in the list of available file types in the preferences list. I am trying to create a manual association, but I am not sure what MIME Type to give it. I encounter these files in my Calibre E-Book software folders. They all open with Notepad ++ but it would be nice to give them a different icon that one since I already use that one for .json files and I have a Python Icon that would be nice to use to differentiate them.


  1. How to get files not already listed into the filetypes menu without manually entering them? Windows already shows the file, but I can't seem to get DOpus to list them.
  2. What is "MIME Type" and how do I know what to associate a file with - what should I put down for .py?
  3. If I open the file with one program "Notepad ++ " but want to use another icon, how can I do that and make sure it doesn't get overridden?

Off Topic--
Ebooks - .mobi, .azw3, .mobi - They are all opened with Calibre E-Book Viewer, but I want them to have their own individual file icons. How to do this - and keep it from reverting back?

  1. / 3. * Either go to file context menu "open with > choose defaul > choose other app" choose the app and tick "use as default program". This is the windows way to register the filetype. Or go to DOpus filetype settings "new > new file type" and apply the desired setings there. Such as icon and default program.

Thanks, I was able to add it and now it has an icon! - I had to add the text/x-py to the MIME though

Nir Sofer/FilesTypeMan (NirSoft) can be a good choice...