[gzread]

I write assert(a==1) right before the line where a is assumed to be 1 (to skip a division by a) even if I know it's 1. Especially if I know it's 1!

[zahlman]

The assertion here is not about implementation logic. GP presumably has in mind unit tests, specifically in a framework where the test logic is implemented with such assertions. (For the Python ecosystem, pytest is pretty much standard, and works that way.)