assert statements in the code

[Gabriel2409]

I noticed that the code contains assert statements at certain places. For example, the load function of Config

def load(self) -> None:
    assert not self.loaded
    if self.is_ssl:
        assert self.ssl_certfile
        self.ssl: ssl.SSLContext | None = create_ssl_context(...)
        ...

If we consider the following code

# here app can be anything, for ex app = Fastapi()
uvicorn.run("main:app", port=8000, log_level="debug", ssl_keyfile="does_not_exist")

we get an assertion error because self.is_ssl is set to True and self_certfile is None

---

We can disable assertions by running python with the -O flag (for ex in prod). So if we run again with the -O flag, assertion is bypassed and we actually go into the create_ssl_context function before getting a TypeError: certfile should be a valid filesystem path

So my questions is: Are there good reasons to use assert statements instead of just raising an error so that behavior is similar with and without optimization?

Maybe it is because the assert statements here don't protect anything and are just there to help developers.
Anyways, I would love to hear your thoughts on that.

Thank you.