I have programmed for quite a long time in both Python and Go and I also experimented with rewriting the same solution in each language - for smaller projects.
Performance Go of course beats Python in almost all aspects, but what about productivity?
My experience is in general Python is a lot more productive, with less code but if you don't take care of keeping things well-organized then the productivity falls for bigger projects. While on the other hand, Go seems to be more linear (similar) productivity even if you have a larger code base.
What is your experience with productivity, especially as the project matures?
In my personal experience, python is great for prototyping, but you'll be in growth pain, sometimes even as early as a hundred active users.
On the other hand, for me go is almost as productive as python. If i work in a team, i'd even say go is more productive. The simplicity and straightforwardness of go really saves a lot of trouble.
My personal preference of the two is Go, but i'd only use it if the code itself is important part for the product.
If the goal is to develop something for the web quickly, i'd use neither. They both have very basic UI features. Something like PHP or nodejs will give you results much quicker.
A big lesson for me was that quickly delivered questionable-quality software is usually more successful than great software with slightly slower development cycle. Go was not the right choice for the former.