dirs: convert PyString to PyBytes PyStringObject was renamed to PyBytes in Python 3 along with the corresponding PyString* functions and macros. PyString* doesn't exist in Python 3. But PyBytes* is an alias to PyString in Python 2. So rewrite PyString* to PyBytes* for Python 2/3 dual compatibility.

dirs: inline string macros The old code happened to work because of how the macro was defined. This no longer works in Python 3. Furthermore, assigning to a macro just feels weird. So just inline the macro.

parsers: use PyVarObject_HEAD_INIT The macro changed slightly in Python 3, introducing curly brackets that somehow confuse Clang into issuing a ton of compiler warnings. Using PyVarObject_HEAD_INIT makes these go away. It's worth noting that the code is identical: the 2nd argument to PyVarObject_HEAD_INIT is assigned to the ob_size field and is inserted immediately after "PyObject_HEAD_INIT(type)" is generated. Compilers are weird.