I've read that when python evaluates a conditional, that something like if x: would be translated to if bool(x):. Why then do I see a lot of code that calls bool() directly? Is this mostly for readability or is there some other advantage?
The bool() in if bool(x): is entirely redundant. if will do the exact same thing already.
If you see code that does this (use bool() in a context where truth-testing already is taking place, such as an if or while statement), then there is no advantage whatsoever. In such contexts the truth value of the object is tested, you don't need to convert it to a boolean first, that just creates double work.
Use bool() only when you need to explicitly convert to a boolean object; for example when storing the result in a variable or passing it to a function that needs to have a boolean value, or as if your function is documented as returning a boolean.