Python/Django or C#/ASP.NET for web development?
Much as I love Python (and, that's a LOT!-), if you're highly skilled at C# and, as you say, "have no experience on Python", your code will be more scalable and suitable (for the next several months, at least) if you stick with what you know best. For a hypothetical developer extremely skilled at both platforms, scalability would essentially be a wash, and Python would enhance that developer's productivity; but getting really good at any technology takes some months of practice, it doesn't "just happen" magically.
So, unless you're trying to broaden your range of skills and job opportunities, or enhance your productivity, but rather are specifically, strictly focused on the scalability of the web apps you're coding right now, I have, in good conscience, to recommend you stick with C#. You should also try IronPython (and get the great "IronPython in Action" book from Mannings -- bias alert, I'm friends with the author and was a tech reviewer of that book;-) for all sorts of non-production supporting code, to get a taste of it and the incredible productivity boost it can give you... but, to deliver best value to your clients or employers, stick with what you REALLY master, C#, for any scalability-critical work you deliver to them!
I am a .NET developer. I have no experience on Python. Which platform is more scalable? Which platform is more suitable for large-size high-traffic web sites? If you have any experience about scalability on these platforms, please inform us.
Thank you.