message: Fixed python 3 issue with string attr values.
diff: @@ -46,12 +46,11 @@ namespace {
  #if PY_MAJOR_VERSION >= 3
  PARSE_VALUE(ParseIntValue, int, PyLong_Check, PyLong_AsLong)
  PARSE_VALUE(ParseInt64Value, int64_t, PyLong_Check, PyLong_AsLong)
  -PARSE_VALUE(ParseStringValue, const char*, PyUnicode_Check, PyUnicode_AsUTF8)
  #else
  -PARSE_VALUE(ParseStringValue, const char*, PyString_Check, PyString_AsString)
  PARSE_VALUE(ParseIntValue, int, PyInt_Check, PyInt_AsLong)
  PARSE_VALUE(ParseInt64Value, int64_t, PyInt_Check, PyInt_AsLong)
  #endif
  +PARSE_VALUE(ParseStringValue, const char*, PyBytes_Check, PyBytes_AsString)
  PARSE_VALUE(ParseFloatValue, float, PyFloat_Check, PyFloat_AsDouble)
  #undef PARSE_VALUE
  