I watched the PyCon keynote on this topic, and while it's nice to hear they've moved to Python3 their approach probably shouldn't be copied.
For example, in their codebase they had ambiguity between bytestrings and unicode strings. As Python3 tries to prevent you doing this, to resolve a big footgun from Python2.
The right fix here is to be consistent in your use of strings. Sometimes that is tricky because of how third party libraries have decided to implement their 2/3 compatibility, but it helps prevent shooting yourself in the foot with unicode bugs down the line.
Instagram did not do this. They created utility functions to force their data into the format they wanted at the point it is used. In other places they used tuple() to make sure that map calls that had side effects were fully iterated over.
In short, they had bad Python2 code and now have had Python3 code. Sometimes, at large scale, it's your only choice. But to smaller companies looking at this it's a bad idea. You're setting a precedent in your code that it's okay to make the same mistakes that Python3 tried to prevent.
For example, in their codebase they had ambiguity between bytestrings and unicode strings. As Python3 tries to prevent you doing this, to resolve a big footgun from Python2.
The right fix here is to be consistent in your use of strings. Sometimes that is tricky because of how third party libraries have decided to implement their 2/3 compatibility, but it helps prevent shooting yourself in the foot with unicode bugs down the line.
Instagram did not do this. They created utility functions to force their data into the format they wanted at the point it is used. In other places they used tuple() to make sure that map calls that had side effects were fully iterated over.
In short, they had bad Python2 code and now have had Python3 code. Sometimes, at large scale, it's your only choice. But to smaller companies looking at this it's a bad idea. You're setting a precedent in your code that it's okay to make the same mistakes that Python3 tried to prevent.