I can't tell if you're trolling or not, but this is a ridiculous thing either wya.

I've used Python as my main language for ~10 years in various professional roles (DS, DE, SWE) and I so rarely need the exact construction `substring in string` that I probably would have blanked on it too in an interview. 99% of my string processing is .startswith/.endswith and re.search, that's just the way it goes. Hell, I know the difference between re.search and re.match by heart (do you? no? you're substandard!) but I genuinely forgot that `in` works on strings.