If your goal is to prove your Python expertise to recruiters and employers, then I'd say yes, go ahead!
I also enjoy the way you write tech articles: they are clear and visually compelling. If you think that these skills will help you get a dream job - go ahead (2)!
I think the domain doesn't matter as long as you don't want to make your blog a part of your personal brand. If blogging is like a hobby to you, then leave it as it is. You want to build a strong brand around your name, meaning investing a lot of time, building a community, giving tech talks, etc. than you need a personal domain to make you blog look professional :)