The point is that they think they understand it, because most of Python behaves the same in development and production. You see this function called 'assert', it gives the right error at the right time, and all is good. Then you push it to production and it stops throwing errors. Eventually, you read the manual and it tells you that this specific function is ignored in production. This is a surprise because, say, print doesn't behave like that.
That only happens if you have different production and development environment settings though -- in which case you should expect the different results.
In this particular case, you compiled your code with "-O", so it's not the "same code" used in production, but code compiled with a different flag. Shouldn't they check what the flag does?
The developer may be deploying code to a server they didn't configure.
I agree with the way it's done in Python, as it's consistent with most other languages. But the blog post is right to point out to inexperienced developers that the way assert behaves might give them a surprise.
