Text files open with pdf reader instead of Sublime

I have Ubuntu 16.04. For some reason, the way text files were opened changed a few days ago. Before, all of them opened with Sublime. Now, they open with a pdf reader. Text files have "Python File (no console)" as Type. What's the problem? I can't really remember which was the extension of the text files before, as I never paid attention to this. So can't tell if the change is due to the new file type or the application linked to such file type. I had a look at ~/.local/share/applications/mimeapps.list but it's almost empty. The file defaults.list has: [Default Applications] text/plain=sublime_text.desktop which suggests to me the problem is the Python File extension. I haven't tried to change the extension of the files, as I don't know that's the problem (nor how to do it). Any ideas?