I'd argue the short and long term gains of this approach. If you hire someone who's really good at Python, you're going to get good quality out of the gate fro

I'd argue the short and long term gains of this approach. If you hire someone who's really good at Python, you're going to get good quality out of the gate from them. But if they're not a good fit for your company or team and/or if they're not passionate about what they do, you might be damaging progress or performance in the long run. In that case I'd take a .NET developer willing to become a good Python developer over a Python developer who's there to collect a paycheque anyday. That being said, if you can find a great Python developer who is also passionate and a good fit, you've hit the jackpot!