Not to get into an API argument, but rather to convey some Python philosophy as I understand it: there *is* often a distinction in Python between the value 'None' and a boolean-False-value like ''.  It is often the case in Python APIs that None means something different from other arguably-semantically-equivalent values.  In this case I believe it is entirely logical that 'None' (the default value) for a method that does not normally take a body and makes a distinction based on Content-Length (or some other header) makes sense, and that explicitly saying "I want an empty body, including the standard headers" is actually a sensible Python API.  If we were designing it from scratch with these issues in mind, we might well come up with exactly what we've got...or we might not, because wanting to specify an empty body on such a command is a really low probability event :)

Regardless, we're constrained by backward compatibility here, so the question is moot.