[Python-Dev] str() vs format(): trivia question

urllib.urlencode currently uses `str()` on its non-bytes objects before encoding the result. This causes a compatibility break when integer module constants are converted to IntEnum, as `str(IntEnum.MEMBER)` no longer returns the integer representation; however, `format()` does still return the integer representation. The fix is to add a separate branch to check if the argument is an Enum, and use the value if so -- but it got me wondering: in general, are there differences between calling str() vs calling format() on Python objects? -- ~Ethan~